QUOTE (Bloy+Dec 22 2005, 08:07 PM)
oh boy! only 13 more pages to reach 200 !!!! 
...and as "Blood Sweat and Tears" group played...Where do we go from here?
I take it then that we all agree that any type of vehicle( human or otherwise) WILL accelerate on the conveyor and move forward. NO standing still....unless NO movement from both the conveyor and propelled object on it.
yeee hah! I'm wallowing in my shortlived "last word"....
VERY "shortlived" indeed !!!!
...and as "Blood Sweat and Tears" group played...Where do we go from here?
I take it then that we all agree that any type of vehicle( human or otherwise) WILL accelerate on the conveyor and move forward. NO standing still....unless NO movement from both the conveyor and propelled object on it.
yeee hah! I'm wallowing in my shortlived "last word".... VERY "shortlived" indeed !!!!
QUOTE (Illiac+Dec 22 2005, 12:28 PM)
QUOTE (SkiSTX+Dec 22 2005, 04:01 PM)
re: the car.
There are obviously 2 trains of thought here. And it has to do with how the phrase "moves forward" is interpreted. You can either take it to mean in relation to the belt or in relation to the tower/ground/calm air.
1--
If the 'speed' of the two objects is measured by radar guns from the tower which have to match each other at all times, then the car will achieve wind flow over it's wings. And the speeds could be as follows...
car radar speed = 50
belt radar speed = 50
wheel speed/car speedometer = 100
air speed over wings = 50
2--
If the 'speed' of the two objects is measured based on their own speedometers which have to match each other at all times, then the car will have zero wind over it's wings. And the speeds could be as follows...
car speedometer speed = 50
belt speedometer speed = 50
wheel speed/car speedometer = 50
air speed over wings = 0
--
So neither side is right or wrong... just a different interpretation of the question which doesn't explicitly state what 'moves forward' really means.
However, in scenario 2, the speedometer of the car is measuring it's speed in relation to the belt, and the belt is measuring it's speed in relation to the dirt beneath it. Is this wrong? Not necessarily, but I think it would be more correct/scientific to measure both speeds in relation to the same object as per scenario 1.
So I will agree to disagree with the 'car no flyiers'.
BTW I don't mean to put words in anyones mouth... this is just the way I am interpreting the two sides of the argument.
SkiSTX,
I think that Atl5p, Fargo and I (plus a few unidentified Guests) long ago agreed that there were two possible interpretations.
1. Speed of the plane is measured as movement forward from a stationary observer. This interpretation totally discounts any effect from the belt because it already says that the plane is moving forward away from a stationary observer and hence all actions of the belt must be netted out for that to occur. If that is your definition, then of course the problem is trivial and the plane will fly.
2. Speed of the plane is measured relative to the belt, just like you see on a treadmill in a gym a millions of times per day. The plane moves forward relative to the belt in one direction and the belt moves in the opposite direction at the same speed and the plane is stationary with respect to an outside observer, thus no airspeed and it will not fly.
The problem here has been a total refusal of the "it will fly" folks to acknowledge the second interpretation which has been muddled by all sorts of "new physics" such as "free wheeling", to support their claim that even if you did interpret the problem as case #2, the plane still would fly because there's nothing the conveyor could do to stop the forward motion of the plane. Now it seems that while there be some acknowledgment that #2 is possible, they want to argue that #1 is a "more correct interpretation" or even more amazing, that you couldn't build a controller to work for case #2 so therefore #1 has to be the only possible interpretation...incredible!! Now I am reading a post that suggests that you might be able to get a close match of speeds but that the plane would inch forward every so slightly so therefore it would always have the advantage over the belt....give me a break!! Certainly, you could just put a light sensor at the side of the conveyor about an inch ahead of the plane's wheel and when the wheel triggers the light, speed up the conveyor until the sensor goes out and with some smoothing intellegence the whole thing could probably match speeds within +- a couple inches/sec....that's not close enough??
Remember that the it will fly folks have to own up to a long history of posts about "free wheeling" which has been used both to support their case for interpretation #1 and also to refute all possibility of interpretation #2. I think that a new thread should be started on that topic alone just to capture the madness in one place.
I also think it has been interesting to note the difference in civility between the "it will fly" posters versus the "no fly" posters...wonder why that is? Alt5p has born the brunt of this because he's obviously put a LOT more energy into this debate but has for the most part (OK, one bad night) been extremely patient and civil.
Certainly this has been an interesting problem and a demonstration that any "learning" by web board is probably a futile effort as I don't see anyone changing their original stance on the problem after nearly 200 pages of argument.
Looks like I'll have to do this again...
The second interpretation violates that original question!
"The plane moves in one direction, while the conveyer moves in the opposite direction."
This implies a single unified reference frame outside both the plane and belt (ie... The ground!) Interpreting it as measuring one in terms of the other is a non sequitur.
"This conveyer has a control system that tracks the plane speed and tunes the speed of the conveyer to be exactly the same (but in opposite direction)."
"but in opposite direction" implies that the belt is not instantaneous in its measurement and since a second reference frame is not given, then only one can be assumed, the ground reference frame is to be used to measure the speed of the plane. Not to mention that speed is defined as distance per unit time. If it is instantaneous time is zero and you have a divide by zero...and an infinite acceleration of the wheels. And they call our logic flawed!
The second interpretation violates that original question!
"The plane moves in one direction, while the conveyer moves in the opposite direction."
This implies a single unified reference frame outside both the plane and belt (ie... The ground!) Interpreting it as measuring one in terms of the other is a non sequitur.
"This conveyer has a control system that tracks the plane speed and tunes the speed of the conveyer to be exactly the same (but in opposite direction)."
"but in opposite direction" implies that the belt is not instantaneous in its measurement and since a second reference frame is not given, then only one can be assumed, the ground reference frame is to be used to measure the speed of the plane. Not to mention that speed is defined as distance per unit time. If it is instantaneous time is zero and you have a divide by zero...and an infinite acceleration of the wheels. And they call our logic flawed!
"new physics" such as "free wheeling"
New?? I think the wheel was invented at least ten thousand yeas ago! Not what I would call new! The term "free wheeling" refers to the fact that the brakes are not on! (Again, an extremely difficult concept to grasp) You can see that their interpretation is flawed!
The light sensor he mentions, tracks the planes position of the plane not speed... again violating the original conditions of the question.
He is also forgetting that for a very long time they interpreted the question as we did, and they were saying that the friction in the wheels coupled with the planes weight, would not allow the plane to move forward.
( pages in the 50's .. 90's )
Pounding our head against a wall... and beating a dead horse all come to mind!
It's been evident throughout that their knowledge of physics and physical concepts as well as critical thinking skills are all lacking! As a matter of fact, Atl5p has actually learned quite a bit. If you go back and read his early posts they were horrible! The later ones, although still flawed showed much improvement in terminology and understanding.
Krreagan
There are obviously 2 trains of thought here. And it has to do with how the phrase "moves forward" is interpreted. You can either take it to mean in relation to the belt or in relation to the tower/ground/calm air.
1--
If the 'speed' of the two objects is measured by radar guns from the tower which have to match each other at all times, then the car will achieve wind flow over it's wings. And the speeds could be as follows...
car radar speed = 50
belt radar speed = 50
wheel speed/car speedometer = 100
air speed over wings = 50
2--
If the 'speed' of the two objects is measured based on their own speedometers which have to match each other at all times, then the car will have zero wind over it's wings. And the speeds could be as follows...
car speedometer speed = 50
belt speedometer speed = 50
wheel speed/car speedometer = 50
air speed over wings = 0
--
So neither side is right or wrong... just a different interpretation of the question which doesn't explicitly state what 'moves forward' really means.
However, in scenario 2, the speedometer of the car is measuring it's speed in relation to the belt, and the belt is measuring it's speed in relation to the dirt beneath it. Is this wrong? Not necessarily, but I think it would be more correct/scientific to measure both speeds in relation to the same object as per scenario 1.
So I will agree to disagree with the 'car no flyiers'.
BTW I don't mean to put words in anyones mouth... this is just the way I am interpreting the two sides of the argument.
SkiSTX,
I think that Atl5p, Fargo and I (plus a few unidentified Guests) long ago agreed that there were two possible interpretations.
1. Speed of the plane is measured as movement forward from a stationary observer. This interpretation totally discounts any effect from the belt because it already says that the plane is moving forward away from a stationary observer and hence all actions of the belt must be netted out for that to occur. If that is your definition, then of course the problem is trivial and the plane will fly.
2. Speed of the plane is measured relative to the belt, just like you see on a treadmill in a gym a millions of times per day. The plane moves forward relative to the belt in one direction and the belt moves in the opposite direction at the same speed and the plane is stationary with respect to an outside observer, thus no airspeed and it will not fly.
The problem here has been a total refusal of the "it will fly" folks to acknowledge the second interpretation which has been muddled by all sorts of "new physics" such as "free wheeling", to support their claim that even if you did interpret the problem as case #2, the plane still would fly because there's nothing the conveyor could do to stop the forward motion of the plane. Now it seems that while there be some acknowledgment that #2 is possible, they want to argue that #1 is a "more correct interpretation" or even more amazing, that you couldn't build a controller to work for case #2 so therefore #1 has to be the only possible interpretation...incredible!! Now I am reading a post that suggests that you might be able to get a close match of speeds but that the plane would inch forward every so slightly so therefore it would always have the advantage over the belt....give me a break!! Certainly, you could just put a light sensor at the side of the conveyor about an inch ahead of the plane's wheel and when the wheel triggers the light, speed up the conveyor until the sensor goes out and with some smoothing intellegence the whole thing could probably match speeds within +- a couple inches/sec....that's not close enough??
Remember that the it will fly folks have to own up to a long history of posts about "free wheeling" which has been used both to support their case for interpretation #1 and also to refute all possibility of interpretation #2. I think that a new thread should be started on that topic alone just to capture the madness in one place.
I also think it has been interesting to note the difference in civility between the "it will fly" posters versus the "no fly" posters...wonder why that is? Alt5p has born the brunt of this because he's obviously put a LOT more energy into this debate but has for the most part (OK, one bad night) been extremely patient and civil.
Certainly this has been an interesting problem and a demonstration that any "learning" by web board is probably a futile effort as I don't see anyone changing their original stance on the problem after nearly 200 pages of argument.
Looks like I'll have to do this again...
QUOTE
A plane is standing on runway that can move (some sort of band conveyer). The plane moves in one direction, while the conveyer moves in the opposite direction. This conveyer has a control system that tracks the plane speed and tunes the speed of the conveyer to be exactly the same (but in opposite direction).
The question is:
Will the plane take off or not? Will it be able to run up and take off?
The question is:
Will the plane take off or not? Will it be able to run up and take off?
The second interpretation violates that original question!
"The plane moves in one direction, while the conveyer moves in the opposite direction."
This implies a single unified reference frame outside both the plane and belt (ie... The ground!) Interpreting it as measuring one in terms of the other is a non sequitur.
"This conveyer has a control system that tracks the plane speed and tunes the speed of the conveyer to be exactly the same (but in opposite direction)."
"but in opposite direction" implies that the belt is not instantaneous in its measurement and since a second reference frame is not given, then only one can be assumed, the ground reference frame is to be used to measure the speed of the plane. Not to mention that speed is defined as distance per unit time. If it is instantaneous time is zero and you have a divide by zero...and an infinite acceleration of the wheels. And they call our logic flawed!
QUOTE (->
| QUOTE |
| A plane is standing on runway that can move (some sort of band conveyer). The plane moves in one direction, while the conveyer moves in the opposite direction. This conveyer has a control system that tracks the plane speed and tunes the speed of the conveyer to be exactly the same (but in opposite direction). The question is: Will the plane take off or not? Will it be able to run up and take off? |
The second interpretation violates that original question!
"The plane moves in one direction, while the conveyer moves in the opposite direction."
This implies a single unified reference frame outside both the plane and belt (ie... The ground!) Interpreting it as measuring one in terms of the other is a non sequitur.
"This conveyer has a control system that tracks the plane speed and tunes the speed of the conveyer to be exactly the same (but in opposite direction)."
"but in opposite direction" implies that the belt is not instantaneous in its measurement and since a second reference frame is not given, then only one can be assumed, the ground reference frame is to be used to measure the speed of the plane. Not to mention that speed is defined as distance per unit time. If it is instantaneous time is zero and you have a divide by zero...and an infinite acceleration of the wheels. And they call our logic flawed!
"new physics" such as "free wheeling"
New?? I think the wheel was invented at least ten thousand yeas ago! Not what I would call new! The term "free wheeling" refers to the fact that the brakes are not on! (Again, an extremely difficult concept to grasp) You can see that their interpretation is flawed!
The light sensor he mentions, tracks the planes position of the plane not speed... again violating the original conditions of the question.
He is also forgetting that for a very long time they interpreted the question as we did, and they were saying that the friction in the wheels coupled with the planes weight, would not allow the plane to move forward.
( pages in the 50's .. 90's )Pounding our head against a wall... and beating a dead horse all come to mind!
It's been evident throughout that their knowledge of physics and physical concepts as well as critical thinking skills are all lacking! As a matter of fact, Atl5p has actually learned quite a bit. If you go back and read his early posts they were horrible! The later ones, although still flawed showed much improvement in terminology and understanding.
Krreagan
QUOTE (Guest+Dec 22 2005, 01:22 PM)
Your right it might just reach 200.
Time to start transferring my kids to any school other than the no fly-ers went to.
Since Atl5p mentioned www.howstuffworks.com so much... I would assume he's home schooled!
Krreagan
Time to start transferring my kids to any school other than the no fly-ers went to.
Since Atl5p mentioned www.howstuffworks.com so much... I would assume he's home schooled!
Krreagan
QUOTE (Fynlcut+Dec 22 2005, 02:33 PM)
QUOTE (Bloy+Dec 22 2005, 02:19 PM)
QUOTE (Fynlcut+Dec 22 2005, 02:14 PM)
QUOTE (Bloy+Dec 22 2005, 01:51 PM)
QUOTE (Fynlcut+Dec 22 2005, 01:41 PM)
QUOTE (Bloy+Dec 22 2005, 01:10 PM)
QUOTE (Fynlcut+Dec 22 2005, 12:58 PM)
QUOTE (Bloy+Dec 22 2005, 12:52 PM)
I would suggest you experiment with different waxes applied to the floats to find the best typw for least resistance.. 
??
I'm talking boats. Will a boat go faster in a lake of alcohol or in a lake of slightly warmed maple syrup?
Prop is more eficient in the syrup, but it's harder to ove the boat , yet it does not displace as much liquid. The prop is less efficient in alcohol, but the boat displaces more liquid, but has less resistance to the boat passing through it.
yes skiers/snowboarders use different waxes for different temps and snow conditions.
isn't a boat a float? and as for the prop.... I know of props on planes that change pitch, but I'm not sure if boat props can be made to do so also...
I don't keep up with boating much, but I don't know of any variable props.
I think you have to pick the best one for the job and use it.
Boats float, but they are not a float. They are a boat. Floats are not self propelled.
well...you could go with a "swamp boat" that uses "air" to propel it. Then you could make use of the variable pitch mechanism and if you are hopping from one poluted area to another with variable viscosity(a pool of thick oil spill) you could change the prop pitch for maximize performance.
That could work, but maybe it would be more eficient to have a a 5 speed manuall transmission. That way I could alway run the engine at optimum RPM.
Hell... lets just go with a "hover craft" and avoid all the sludge or viscosity factors all together...
...er.. we'll still have to figure in the "density" of the atmosphere...
but the fresh paint job on the vehicle would remain somewhat clean...depending on how much spray the viscous fluid releases into the atmosphere.
On second thought(or third or fourth), your boat seems the most environmently harmonious..
Perhaps I should let the EPA clean up the mess befor I go boating.
I thought I'd go back a few pages, find a relatively long post and post it here..just to help move the page count along....
??
I'm talking boats. Will a boat go faster in a lake of alcohol or in a lake of slightly warmed maple syrup?
Prop is more eficient in the syrup, but it's harder to ove the boat , yet it does not displace as much liquid. The prop is less efficient in alcohol, but the boat displaces more liquid, but has less resistance to the boat passing through it.
yes skiers/snowboarders use different waxes for different temps and snow conditions.
isn't a boat a float? and as for the prop.... I know of props on planes that change pitch, but I'm not sure if boat props can be made to do so also...
I don't keep up with boating much, but I don't know of any variable props.
I think you have to pick the best one for the job and use it.
Boats float, but they are not a float. They are a boat. Floats are not self propelled.
well...you could go with a "swamp boat" that uses "air" to propel it. Then you could make use of the variable pitch mechanism and if you are hopping from one poluted area to another with variable viscosity(a pool of thick oil spill) you could change the prop pitch for maximize performance.
That could work, but maybe it would be more eficient to have a a 5 speed manuall transmission. That way I could alway run the engine at optimum RPM.
Hell... lets just go with a "hover craft" and avoid all the sludge or viscosity factors all together...
...er.. we'll still have to figure in the "density" of the atmosphere...
but the fresh paint job on the vehicle would remain somewhat clean...depending on how much spray the viscous fluid releases into the atmosphere.
On second thought(or third or fourth), your boat seems the most environmently harmonious..
Perhaps I should let the EPA clean up the mess befor I go boating.
I thought I'd go back a few pages, find a relatively long post and post it here..just to help move the page count along....
QUOTE (krreagan+Dec 22 2005, 08:24 PM)
QUOTE (Illiac+Dec 22 2005, 12:28 PM)
QUOTE (SkiSTX+Dec 22 2005, 04:01 PM)
re: the car.
There are obviously 2 trains of thought here. And it has to do with how the phrase "moves forward" is interpreted. You can either take it to mean in relation to the belt or in relation to the tower/ground/calm air.
1--
If the 'speed' of the two objects is measured by radar guns from the tower which have to match each other at all times, then the car will achieve wind flow over it's wings. And the speeds could be as follows...
car radar speed = 50
belt radar speed = 50
wheel speed/car speedometer = 100
air speed over wings = 50
2--
If the 'speed' of the two objects is measured based on their own speedometers which have to match each other at all times, then the car will have zero wind over it's wings. And the speeds could be as follows...
car speedometer speed = 50
belt speedometer speed = 50
wheel speed/car speedometer = 50
air speed over wings = 0
--
So neither side is right or wrong... just a different interpretation of the question which doesn't explicitly state what 'moves forward' really means.
However, in scenario 2, the speedometer of the car is measuring it's speed in relation to the belt, and the belt is measuring it's speed in relation to the dirt beneath it. Is this wrong? Not necessarily, but I think it would be more correct/scientific to measure both speeds in relation to the same object as per scenario 1.
So I will agree to disagree with the 'car no flyiers'.
BTW I don't mean to put words in anyones mouth... this is just the way I am interpreting the two sides of the argument.
SkiSTX,
I think that Atl5p, Fargo and I (plus a few unidentified Guests) long ago agreed that there were two possible interpretations.
1. Speed of the plane is measured as movement forward from a stationary observer. This interpretation totally discounts any effect from the belt because it already says that the plane is moving forward away from a stationary observer and hence all actions of the belt must be netted out for that to occur. If that is your definition, then of course the problem is trivial and the plane will fly.
2. Speed of the plane is measured relative to the belt, just like you see on a treadmill in a gym a millions of times per day. The plane moves forward relative to the belt in one direction and the belt moves in the opposite direction at the same speed and the plane is stationary with respect to an outside observer, thus no airspeed and it will not fly.
The problem here has been a total refusal of the "it will fly" folks to acknowledge the second interpretation which has been muddled by all sorts of "new physics" such as "free wheeling", to support their claim that even if you did interpret the problem as case #2, the plane still would fly because there's nothing the conveyor could do to stop the forward motion of the plane. Now it seems that while there be some acknowledgment that #2 is possible, they want to argue that #1 is a "more correct interpretation" or even more amazing, that you couldn't build a controller to work for case #2 so therefore #1 has to be the only possible interpretation...incredible!! Now I am reading a post that suggests that you might be able to get a close match of speeds but that the plane would inch forward every so slightly so therefore it would always have the advantage over the belt....give me a break!! Certainly, you could just put a light sensor at the side of the conveyor about an inch ahead of the plane's wheel and when the wheel triggers the light, speed up the conveyor until the sensor goes out and with some smoothing intellegence the whole thing could probably match speeds within +- a couple inches/sec....that's not close enough??
Remember that the it will fly folks have to own up to a long history of posts about "free wheeling" which has been used both to support their case for interpretation #1 and also to refute all possibility of interpretation #2. I think that a new thread should be started on that topic alone just to capture the madness in one place.
I also think it has been interesting to note the difference in civility between the "it will fly" posters versus the "no fly" posters...wonder why that is? Alt5p has born the brunt of this because he's obviously put a LOT more energy into this debate but has for the most part (OK, one bad night) been extremely patient and civil.
Certainly this has been an interesting problem and a demonstration that any "learning" by web board is probably a futile effort as I don't see anyone changing their original stance on the problem after nearly 200 pages of argument.
Looks like I'll have to do this again...
The second interpretation violates that original question!
"The plane moves in one direction, while the conveyer moves in the opposite direction."
This implies a single unified reference frame outside both the plane and belt (ie... The ground!) Interpreting it as measuring one in terms of the other is a non sequitur.
"This conveyer has a control system that tracks the plane speed and tunes the speed of the conveyer to be exactly the same (but in opposite direction)."
"but in opposite direction" implies that the belt is not instantaneous in its measurement and since a second reference frame is not given, then only one can be assumed, the ground reference frame is to be used to measure the speed of the plane. Not to mention that speed is defined as distance per unit time. If it is instantaneous time is zero and you have a divide by zero...and an infinite acceleration of the wheels. And they call our logic flawed!
The second interpretation violates that original question!
"The plane moves in one direction, while the conveyer moves in the opposite direction."
This implies a single unified reference frame outside both the plane and belt (ie... The ground!) Interpreting it as measuring one in terms of the other is a non sequitur.
"This conveyer has a control system that tracks the plane speed and tunes the speed of the conveyer to be exactly the same (but in opposite direction)."
"but in opposite direction" implies that the belt is not instantaneous in its measurement and since a second reference frame is not given, then only one can be assumed, the ground reference frame is to be used to measure the speed of the plane. Not to mention that speed is defined as distance per unit time. If it is instantaneous time is zero and you have a divide by zero...and an infinite acceleration of the wheels. And they call our logic flawed!
"new physics" such as "free wheeling"
New?? I think the wheel was invented at least ten thousand yeas ago! Not what I would call new! The term "free wheeling" refers to the fact that the brakes are not on! (Again, an extremely difficult concept to grasp) You can see that their interpretation is flawed!
The light sensor he mentions, tracks the planes position of the plane not speed... again violating the original conditions of the question.
He is also forgetting that for a very long time they interpreted the question as we did, and they were saying that the friction in the wheels coupled with the planes weight, would not allow the plane to move forward. ( pages in the 50's .. 90's )
Pounding our head against a wall... and beating a dead horse all come to mind!
It's been evident throughout that their knowledge of physics and physical concepts as well as critical thinking skills are all lacking! As a matter of fact, Atl5p has actually learned quite a bit. If you go back and read his early posts they were horrible! The later ones, although still flawed showed much improvement in terminology and understanding.
Krreagan
another one for the count!
There are obviously 2 trains of thought here. And it has to do with how the phrase "moves forward" is interpreted. You can either take it to mean in relation to the belt or in relation to the tower/ground/calm air.
1--
If the 'speed' of the two objects is measured by radar guns from the tower which have to match each other at all times, then the car will achieve wind flow over it's wings. And the speeds could be as follows...
car radar speed = 50
belt radar speed = 50
wheel speed/car speedometer = 100
air speed over wings = 50
2--
If the 'speed' of the two objects is measured based on their own speedometers which have to match each other at all times, then the car will have zero wind over it's wings. And the speeds could be as follows...
car speedometer speed = 50
belt speedometer speed = 50
wheel speed/car speedometer = 50
air speed over wings = 0
--
So neither side is right or wrong... just a different interpretation of the question which doesn't explicitly state what 'moves forward' really means.
However, in scenario 2, the speedometer of the car is measuring it's speed in relation to the belt, and the belt is measuring it's speed in relation to the dirt beneath it. Is this wrong? Not necessarily, but I think it would be more correct/scientific to measure both speeds in relation to the same object as per scenario 1.
So I will agree to disagree with the 'car no flyiers'.
BTW I don't mean to put words in anyones mouth... this is just the way I am interpreting the two sides of the argument.
SkiSTX,
I think that Atl5p, Fargo and I (plus a few unidentified Guests) long ago agreed that there were two possible interpretations.
1. Speed of the plane is measured as movement forward from a stationary observer. This interpretation totally discounts any effect from the belt because it already says that the plane is moving forward away from a stationary observer and hence all actions of the belt must be netted out for that to occur. If that is your definition, then of course the problem is trivial and the plane will fly.
2. Speed of the plane is measured relative to the belt, just like you see on a treadmill in a gym a millions of times per day. The plane moves forward relative to the belt in one direction and the belt moves in the opposite direction at the same speed and the plane is stationary with respect to an outside observer, thus no airspeed and it will not fly.
The problem here has been a total refusal of the "it will fly" folks to acknowledge the second interpretation which has been muddled by all sorts of "new physics" such as "free wheeling", to support their claim that even if you did interpret the problem as case #2, the plane still would fly because there's nothing the conveyor could do to stop the forward motion of the plane. Now it seems that while there be some acknowledgment that #2 is possible, they want to argue that #1 is a "more correct interpretation" or even more amazing, that you couldn't build a controller to work for case #2 so therefore #1 has to be the only possible interpretation...incredible!! Now I am reading a post that suggests that you might be able to get a close match of speeds but that the plane would inch forward every so slightly so therefore it would always have the advantage over the belt....give me a break!! Certainly, you could just put a light sensor at the side of the conveyor about an inch ahead of the plane's wheel and when the wheel triggers the light, speed up the conveyor until the sensor goes out and with some smoothing intellegence the whole thing could probably match speeds within +- a couple inches/sec....that's not close enough??
Remember that the it will fly folks have to own up to a long history of posts about "free wheeling" which has been used both to support their case for interpretation #1 and also to refute all possibility of interpretation #2. I think that a new thread should be started on that topic alone just to capture the madness in one place.
I also think it has been interesting to note the difference in civility between the "it will fly" posters versus the "no fly" posters...wonder why that is? Alt5p has born the brunt of this because he's obviously put a LOT more energy into this debate but has for the most part (OK, one bad night) been extremely patient and civil.
Certainly this has been an interesting problem and a demonstration that any "learning" by web board is probably a futile effort as I don't see anyone changing their original stance on the problem after nearly 200 pages of argument.
Looks like I'll have to do this again...
QUOTE
A plane is standing on runway that can move (some sort of band conveyer). The plane moves in one direction, while the conveyer moves in the opposite direction. This conveyer has a control system that tracks the plane speed and tunes the speed of the conveyer to be exactly the same (but in opposite direction).
The question is:
Will the plane take off or not? Will it be able to run up and take off?
The question is:
Will the plane take off or not? Will it be able to run up and take off?
The second interpretation violates that original question!
"The plane moves in one direction, while the conveyer moves in the opposite direction."
This implies a single unified reference frame outside both the plane and belt (ie... The ground!) Interpreting it as measuring one in terms of the other is a non sequitur.
"This conveyer has a control system that tracks the plane speed and tunes the speed of the conveyer to be exactly the same (but in opposite direction)."
"but in opposite direction" implies that the belt is not instantaneous in its measurement and since a second reference frame is not given, then only one can be assumed, the ground reference frame is to be used to measure the speed of the plane. Not to mention that speed is defined as distance per unit time. If it is instantaneous time is zero and you have a divide by zero...and an infinite acceleration of the wheels. And they call our logic flawed!
QUOTE (->
| QUOTE |
| A plane is standing on runway that can move (some sort of band conveyer). The plane moves in one direction, while the conveyer moves in the opposite direction. This conveyer has a control system that tracks the plane speed and tunes the speed of the conveyer to be exactly the same (but in opposite direction). The question is: Will the plane take off or not? Will it be able to run up and take off? |
The second interpretation violates that original question!
"The plane moves in one direction, while the conveyer moves in the opposite direction."
This implies a single unified reference frame outside both the plane and belt (ie... The ground!) Interpreting it as measuring one in terms of the other is a non sequitur.
"This conveyer has a control system that tracks the plane speed and tunes the speed of the conveyer to be exactly the same (but in opposite direction)."
"but in opposite direction" implies that the belt is not instantaneous in its measurement and since a second reference frame is not given, then only one can be assumed, the ground reference frame is to be used to measure the speed of the plane. Not to mention that speed is defined as distance per unit time. If it is instantaneous time is zero and you have a divide by zero...and an infinite acceleration of the wheels. And they call our logic flawed!
"new physics" such as "free wheeling"
New?? I think the wheel was invented at least ten thousand yeas ago! Not what I would call new! The term "free wheeling" refers to the fact that the brakes are not on! (Again, an extremely difficult concept to grasp) You can see that their interpretation is flawed!
The light sensor he mentions, tracks the planes position of the plane not speed... again violating the original conditions of the question.
He is also forgetting that for a very long time they interpreted the question as we did, and they were saying that the friction in the wheels coupled with the planes weight, would not allow the plane to move forward.
( pages in the 50's .. 90's )Pounding our head against a wall... and beating a dead horse all come to mind!
It's been evident throughout that their knowledge of physics and physical concepts as well as critical thinking skills are all lacking! As a matter of fact, Atl5p has actually learned quite a bit. If you go back and read his early posts they were horrible! The later ones, although still flawed showed much improvement in terminology and understanding.
Krreagan
another one for the count!
QUOTE (Bloy+Dec 22 2005, 08:27 PM)
QUOTE (Fynlcut+Dec 22 2005, 02:33 PM)
QUOTE (Bloy+Dec 22 2005, 02:19 PM)
QUOTE (Fynlcut+Dec 22 2005, 02:14 PM)
QUOTE (Bloy+Dec 22 2005, 01:51 PM)
QUOTE (Fynlcut+Dec 22 2005, 01:41 PM)
QUOTE (Bloy+Dec 22 2005, 01:10 PM)
QUOTE (Fynlcut+Dec 22 2005, 12:58 PM)
QUOTE (Bloy+Dec 22 2005, 12:52 PM)
I would suggest you experiment with different waxes applied to the floats to find the best typw for least resistance..
??
I'm talking boats. Will a boat go faster in a lake of alcohol or in a lake of slightly warmed maple syrup?
Prop is more eficient in the syrup, but it's harder to ove the boat , yet it does not displace as much liquid. The prop is less efficient in alcohol, but the boat displaces more liquid, but has less resistance to the boat passing through it.
yes skiers/snowboarders use different waxes for different temps and snow conditions.
isn't a boat a float? and as for the prop.... I know of props on planes that change pitch, but I'm not sure if boat props can be made to do so also...
I don't keep up with boating much, but I don't know of any variable props.
I think you have to pick the best one for the job and use it.
Boats float, but they are not a float. They are a boat. Floats are not self propelled.
well...you could go with a "swamp boat" that uses "air" to propel it. Then you could make use of the variable pitch mechanism and if you are hopping from one poluted area to another with variable viscosity(a pool of thick oil spill) you could change the prop pitch for maximize performance.
That could work, but maybe it would be more eficient to have a a 5 speed manuall transmission. That way I could alway run the engine at optimum RPM.
Hell... lets just go with a "hover craft" and avoid all the sludge or viscosity factors all together...
...er.. we'll still have to figure in the "density" of the atmosphere...
but the fresh paint job on the vehicle would remain somewhat clean...depending on how much spray the viscous fluid releases into the atmosphere.
On second thought(or third or fourth), your boat seems the most environmently harmonious..
Perhaps I should let the EPA clean up the mess befor I go boating.
I thought I'd go back a few pages, find a relatively long post and post it here..just to help move the page count along....
By the way.... What would the EPA use to clean up... a boat? or a rope on a float?
??
I'm talking boats. Will a boat go faster in a lake of alcohol or in a lake of slightly warmed maple syrup?
Prop is more eficient in the syrup, but it's harder to ove the boat , yet it does not displace as much liquid. The prop is less efficient in alcohol, but the boat displaces more liquid, but has less resistance to the boat passing through it.
yes skiers/snowboarders use different waxes for different temps and snow conditions.
isn't a boat a float? and as for the prop.... I know of props on planes that change pitch, but I'm not sure if boat props can be made to do so also...
I don't keep up with boating much, but I don't know of any variable props.
I think you have to pick the best one for the job and use it.
Boats float, but they are not a float. They are a boat. Floats are not self propelled.
well...you could go with a "swamp boat" that uses "air" to propel it. Then you could make use of the variable pitch mechanism and if you are hopping from one poluted area to another with variable viscosity(a pool of thick oil spill) you could change the prop pitch for maximize performance.
That could work, but maybe it would be more eficient to have a a 5 speed manuall transmission. That way I could alway run the engine at optimum RPM.
Hell... lets just go with a "hover craft" and avoid all the sludge or viscosity factors all together...
...er.. we'll still have to figure in the "density" of the atmosphere...
but the fresh paint job on the vehicle would remain somewhat clean...depending on how much spray the viscous fluid releases into the atmosphere.
On second thought(or third or fourth), your boat seems the most environmently harmonious..
Perhaps I should let the EPA clean up the mess befor I go boating.
I thought I'd go back a few pages, find a relatively long post and post it here..just to help move the page count along....
By the way.... What would the EPA use to clean up... a boat? or a rope on a float?
Doesn't count if it's padded guys!
Krreagan
Krreagan
QUOTE (krreagan+Dec 22 2005, 08:35 PM)
Doesn't count if it's padded guys!
Krreagan
How about somebody conduct the official POLL of who is here...
FLY vs NO-FLY.
I vote for FLY.
Krreagan
How about somebody conduct the official POLL of who is here...
FLY vs NO-FLY.
I vote for FLY.
QUOTE (QuantumRift+Dec 22 2005, 08:40 PM)
QUOTE (krreagan+Dec 22 2005, 08:35 PM)
Doesn't count if it's padded guys!
Krreagan
How about somebody conduct the official POLL of who is here...
FLY vs NO-FLY.
I vote for FLY.
I make a motion to second that! but we have to wait for Atl5p to wake up and present his findings to the contrary
Krreagan
How about somebody conduct the official POLL of who is here...
FLY vs NO-FLY.
I vote for FLY.
I make a motion to second that! but we have to wait for Atl5p to wake up and present his findings to the contrary
QUOTE (QuantumRift+Dec 22 2005, 01:40 PM)
QUOTE (krreagan+Dec 22 2005, 08:35 PM)
Doesn't count if it's padded guys!
Krreagan
How about somebody conduct the official POLL of who is here...
FLY vs NO-FLY.
I vote for FLY.
Fly!
Krreagan
Krreagan
How about somebody conduct the official POLL of who is here...
FLY vs NO-FLY.
I vote for FLY.
Fly!
Krreagan
QUOTE (krreagan+Dec 22 2005, 08:49 PM)
QUOTE (QuantumRift+Dec 22 2005, 01:40 PM)
QUOTE (krreagan+Dec 22 2005, 08:35 PM)
Doesn't count if it's padded guys!
Krreagan
How about somebody conduct the official POLL of who is here...
FLY vs NO-FLY.
I vote for FLY.
Fly!
Krreagan
okay ...that's three for "fly", and zip for "no fly"
Krreagan
How about somebody conduct the official POLL of who is here...
FLY vs NO-FLY.
I vote for FLY.
Fly!
Krreagan
okay ...that's three for "fly", and zip for "no fly"
QUOTE (QuantumRift+Dec 22 2005, 01:40 PM)
QUOTE (krreagan+Dec 22 2005, 08:35 PM)
Doesn't count if it's padded guys!
Krreagan
How about somebody conduct the official POLL of who is here...
FLY vs NO-FLY.
I vote for FLY.
Since we all know that the law of physics obey the democratic vote! This will determine how the universe will behave until the next poll overrides this definition of reality!
or
"I reject your reality and substitute my own!" A.Savage
Krreagan
Krreagan
How about somebody conduct the official POLL of who is here...
FLY vs NO-FLY.
I vote for FLY.
Since we all know that the law of physics obey the democratic vote! This will determine how the universe will behave until the next poll overrides this definition of reality!
or
"I reject your reality and substitute my own!" A.Savage
Krreagan
QUOTE (krreagan+Dec 22 2005, 09:01 PM)
QUOTE (QuantumRift+Dec 22 2005, 01:40 PM)
QUOTE (krreagan+Dec 22 2005, 08:35 PM)
Doesn't count if it's padded guys!
Krreagan
How about somebody conduct the official POLL of who is here...
FLY vs NO-FLY.
I vote for FLY.
Since we all know that the law of physics obey the democratic vote! This will determine how the universe will behave until the next poll overrides this definition of reality!
Krreagan
Ah, just enter the FORD ROAD TO KONA Sweepstakes (Below)...
LoL..
Krreagan
How about somebody conduct the official POLL of who is here...
FLY vs NO-FLY.
I vote for FLY.
Since we all know that the law of physics obey the democratic vote! This will determine how the universe will behave until the next poll overrides this definition of reality!
Krreagan
Ah, just enter the FORD ROAD TO KONA Sweepstakes (Below)...
LoL..
QUOTE (Bloy+Dec 22 2005, 08:52 PM)
QUOTE (krreagan+Dec 22 2005, 08:49 PM)
QUOTE (QuantumRift+Dec 22 2005, 01:40 PM)
QUOTE (krreagan+Dec 22 2005, 08:35 PM)
Doesn't count if it's padded guys!
Krreagan
How about somebody conduct the official POLL of who is here...
FLY vs NO-FLY.
I vote for FLY.
Fly!
Krreagan
okay ...that's three for "fly", and zip for "no fly"
fly
Krreagan
How about somebody conduct the official POLL of who is here...
FLY vs NO-FLY.
I vote for FLY.
Fly!
Krreagan
okay ...that's three for "fly", and zip for "no fly"
fly
If you actually did a poll, it would probably turn out exactly the same way it does on almost every other forum: about 3 fly to 1 no fly.
BTW, I'm a flyer.
BTW, I'm a flyer.
FLY!!!!
Fly !
QUOTE (sooks+Dec 22 2005, 07:45 PM)
A lot more "Civility" ........??? Clearly, you missed the part where Atl snapped on me. I mean he lost it..... I know you guys did take it harshly from some before. But it was pretty much unprovoked, i hadnt done any name calling, just simply proving his ideas wrong with the physics.
Atl5p acknowledge that and took the time to appologize. Try to look at the context of the forum at that time with some of your "thought companions" bashing all the no fly guys/gals with I,II,III,IV-type labels which you'll find easy to trace.
Atl5p acknowledge that and took the time to appologize. Try to look at the context of the forum at that time with some of your "thought companions" bashing all the no fly guys/gals with I,II,III,IV-type labels which you'll find easy to trace.
QUOTE (sooks+Dec 22 2005, 07:45 PM)
I dont think most of the will fly guys care much about situation 1 or 2..... whether you use belt or ground...just as long as your consistent with both of them. The main problem most of you no flyers were using is that you had 2 different refernce frames...which is the case where it doesnt work...
But there are two different reference frames. One (the conveyor)determines the speed that the plane is moving down the conveyor and is used in #2 to match the conveyor speed. The other, the outside world is where "apparent motion" (despite the fact that plane may be moving quite fast down the conveyor) determines whether you have airpseed or not. Please refer to any 1st semester college physics class in mechanics and look at problems considering relative motion where one object is moving on the surface of another object, whether the surface is a solid or a fluid. Also, if there are pilots in this debate, surely they must be aware that two reference frames are used ALL THE TIME when considering flight in a moving airmass. Winds aloft give the the speed that an airmass is moving with respect to the ground. Your airspeed in that airmass tells you speed with respect to the airmass. Net the two, with consideration to vectors and you get ground speed...pilots do this everyday...the airmass is like the conveyor, the plane moves within it and the airmass moves in relation to the ground.This problem should be simpler as the vector calculation is trivial. For the life of me, I don't see why pilots of all people in this thread have difficulty accepting that perspective. BTW, what's your groundspeed if you are flying 70kts directly into a headwind of 70kts? Are you moving? Got a lot of fuel?
And, i dont know how you say a LOT more effort into it. THere are plenty of the will fly group (me included) that has spent a lot of time doing some research and running the formulas, using examples, everything to show the physics of it. just to have it thrown out the window and not even acknowledged, but in turn a rsponse comes back that just twists it around another way. I believe thats why you no flyers recieved so much flak is because it was like pulling teeth to get a straight answer. It was amazing how factual information could just be completely ignored. I didnt care if you debated it, or showed it wrong... There was so many times it was just flat out ignored. It starts to get out at people when they spend all that time coming up with a thought out rational explanation, and dont recieve anything back, except for twisting around what they said to something completely the opposite.
QUOTE (sooks+Dec 22 2005, 07:45 PM)
And, i dont know how you say a LOT more effort into it. THere are plenty of the will fly group (me included) that has spent a lot of time doing some research and running the formulas, using examples, everything to show the physics of it. just to have it thrown out the window and not even acknowledged, but in turn a rsponse comes back that just twists it around another way. I believe thats why you no flyers recieved so much flak is because it was like pulling teeth to get a straight answer. It was amazing how factual information could just be completely ignored. I didnt care if you debated it, or showed it wrong... There was so many times it was just flat out ignored. It starts to get out at people when they spend all that time coming up with a thought out rational explanation, and dont recieve anything back, except for twisting around what they said to something completely the opposite.
Sorry, that was not clear on my part, I meant effort relative to other no-fly posters. Face it, Atl5p tried to keep up with all your posts and I can't imagine how much time that took. For a problem who's solution depends only upon "speed", (the only givens in the problem) I think Atl5p certainly went the the distance in trying to accomodate all the challenges into turf such as CRF, total force to move a 747, you name it. You didn't see me respond to all that stuff as I certainly have other things to do and felt it more important to focus on relative motion...beating a dead horse.
No Fly when speed of plane is taken as relative to the conveyor. (My assumption)
Fly if speed of plane is taken as forward motion away from fixed observer. (Not my assumption and not a very interesting problem as speed of plane is the independent variable...what's to determine?)
Fly if speed of plane is taken as forward motion away from fixed observer. (Not my assumption and not a very interesting problem as speed of plane is the independent variable...what's to determine?)
QUOTE (Illiac+Dec 22 2005, 03:07 PM)
No Fly when speed of plane is taken as relative to the conveyor. (My assumption)
Fly if speed of plane is taken as forward motion away from fixed observer. (Not my assumption and not a very interesting problem as speed of plane is the independent variable...what's to determine?)
It's more interesting then the wheels/belt spinning to infinity on first forward motion? That's all your interpretation gives us! A feedback loop that quickly goes out of control!
Krreagan
Fly if speed of plane is taken as forward motion away from fixed observer. (Not my assumption and not a very interesting problem as speed of plane is the independent variable...what's to determine?)
It's more interesting then the wheels/belt spinning to infinity on first forward motion? That's all your interpretation gives us! A feedback loop that quickly goes out of control!
Krreagan
QUOTE (Illiac+Dec 22 2005, 09:57 PM)
QUOTE (sooks+Dec 22 2005, 07:45 PM)
A lot more "Civility" ........??? Clearly, you missed the part where Atl snapped on me. I mean he lost it..... I know you guys did take it harshly from some before. But it was pretty much unprovoked, i hadnt done any name calling, just simply proving his ideas wrong with the physics.
Atl5p acknowledge that and took the time to appologize. Try to look at the context of the forum at that time with some of your "thought companions" bashing all the no fly guys/gals with I,II,III,IV-type labels which you'll find easy to trace.
Atl5p acknowledge that and took the time to appologize. Try to look at the context of the forum at that time with some of your "thought companions" bashing all the no fly guys/gals with I,II,III,IV-type labels which you'll find easy to trace.
QUOTE (sooks+Dec 22 2005, 07:45 PM)
I dont think most of the will fly guys care much about situation 1 or 2..... whether you use belt or ground...just as long as your consistent with both of them. The main problem most of you no flyers were using is that you had 2 different refernce frames...which is the case where it doesnt work...
But there are two different reference frames. One (the conveyor)determines the speed that the plane is moving down the conveyor and is used in #2 to match the conveyor speed. The other, the outside world is where "apparent motion" (despite the fact that plane may be moving quite fast down the conveyor) determines whether you have airpseed or not. Please refer to any 1st semester college physics class in mechanics and look at problems considering relative motion where one object is moving on the surface of another object, whether the surface is a solid or a fluid. Also, if there are pilots in this debate, surely they must be aware that two reference frames are used ALL THE TIME when considering flight in a moving airmass. Winds aloft give the the speed that an airmass is moving with respect to the ground. Your airspeed in that airmass tells you speed with respect to the airmass. Net the two, with consideration to vectors and you get ground speed...pilots do this everyday...the airmass is like the conveyor, the plane moves within it and the airmass moves in relation to the ground.This problem should be simpler as the vector calculation is trivial. For the life of me, I don't see why pilots of all people in this thread have difficulty accepting that perspective. BTW, what's your groundspeed if you are flying 70kts directly into a headwind of 70kts? Are you moving? Got a lot of fuel?
And, i dont know how you say a LOT more effort into it. THere are plenty of the will fly group (me included) that has spent a lot of time doing some research and running the formulas, using examples, everything to show the physics of it. just to have it thrown out the window and not even acknowledged, but in turn a rsponse comes back that just twists it around another way. I believe thats why you no flyers recieved so much flak is because it was like pulling teeth to get a straight answer. It was amazing how factual information could just be completely ignored. I didnt care if you debated it, or showed it wrong... There was so many times it was just flat out ignored. It starts to get out at people when they spend all that time coming up with a thought out rational explanation, and dont recieve anything back, except for twisting around what they said to something completely the opposite.
QUOTE (sooks+Dec 22 2005, 07:45 PM)
And, i dont know how you say a LOT more effort into it. THere are plenty of the will fly group (me included) that has spent a lot of time doing some research and running the formulas, using examples, everything to show the physics of it. just to have it thrown out the window and not even acknowledged, but in turn a rsponse comes back that just twists it around another way. I believe thats why you no flyers recieved so much flak is because it was like pulling teeth to get a straight answer. It was amazing how factual information could just be completely ignored. I didnt care if you debated it, or showed it wrong... There was so many times it was just flat out ignored. It starts to get out at people when they spend all that time coming up with a thought out rational explanation, and dont recieve anything back, except for twisting around what they said to something completely the opposite.
Sorry, that was not clear on my part, I meant effort relative to other no-fly posters. Face it, Atl5p tried to keep up with all your posts and I can't imagine how much time that took. For a problem who's solution depends only upon "speed", (the only givens in the problem) I think Atl5p certainly went the the distance in trying to accomodate all the challenges into turf such as CRF, total force to move a 747, you name it. You didn't see me respond to all that stuff as I certainly have other things to do and felt it more important to focus on relative motion...beating a dead horse.
okay, now bring that 70kts down to the conveyor....
Is the conveyor moving? NO. Because there is no forward motion of the plane..
This is a similar situation when AI was at the EAA convention in Oshkosh(several times)....
When the wind storm came in, all the ultra-light pilots ran to their planes. we were just beyond a tall hedge. The planes took off practically vertically, needing only a small movment along the runway. we couldn't actually see them lift off, but they sounded like a bunch of bumble bees buzzing up into the air..
okay, now bring that 70kts down to the conveyor....
Is the conveyor moving? NO. Because there is no forward motion of the plane..
This is a similar situation when AI was at the EAA convention in Oshkosh(several times)....
When the wind storm came in, all the ultra-light pilots ran to their planes. we were just beyond a tall hedge. The planes took off practically vertically, needing only a small movment along the runway. we couldn't actually see them lift off, but they sounded like a bunch of bumble bees buzzing up into the air..
QUOTE (Illiac+Dec 22 2005, 07:28 PM)
SkiSTX,
I think that Atl5p, Fargo and I (plus a few unidentified Guests) long ago agreed that there were two possible interpretations. EH?
1. Speed of the plane is measured as movement forward from a stationary observer. This interpretation totally discounts any effect from the belt because it already says that the plane is moving forward away from a stationary observer and hence all actions of the belt must be netted out for that to occur. If that is your definition, then of course the problem is trivial and the plane will fly. WHAT???
2. Speed of the plane is measured relative to the belt, just like you see on a treadmill in a gym a millions of times per day. The plane moves forward relative to the belt in one direction and the belt moves in the opposite direction at the same speed and the plane is stationary with respect to an outside observer, thus no airspeed and it will not fly. WHAT???
The problem here has been a total refusal of the "it will fly" folks to acknowledge the second interpretation which has been muddled by all sorts of "new physics" such as "free wheeling", to support their claim that even if you did interpret the problem as case #2, the plane still would fly because there's nothing the conveyor could do to stop the forward motion of the plane. Now it seems that while there be some acknowledgment that #2 is possible, they want to argue that #1 is a "more correct interpretation" or even more amazing, that you couldn't build a controller to work for case #2 so therefore #1 has to be the only possible interpretation...incredible!! WHAT??? Now I am reading a post that suggests that you might be able to get a close match of speeds but that the plane would inch forward every so slightly so therefore it would always have the advantage over the belt....give me a break!! WHAT??? Certainly, you could just put a light sensor at the side of the conveyor about an inch ahead of the plane's wheel and when the wheel triggers the light, speed up the conveyor until the sensor goes out and with some smoothing intellegence the whole thing could probably match speeds within +- a couple inches/sec....that's not close enough?? WHAT???
Remember that the it will fly folks have to own up to a long history of posts about "free wheeling" which has been used both to support their case for interpretation #1 and also to refute all possibility of interpretation #2. WHAT??? I think that a new thread should be started on that topic alone just to capture the madness in one place.
I also think it has been interesting to note the difference in civility between the "it will fly" posters versus the "no fly" posters...wonder why that is? BECAUSE YOU TAKE PRIDE AT BEING STUPID!! Alt5p has born the brunt of this because he's obviously put a LOT more energy into this debate but has for the most part (OK, one bad night) been extremely patient and civil. WHAT???
Certainly this has been an interesting problem and a demonstration that any "learning" by web board is probably a futile effort as I don't see anyone changing their original stance on the problem after nearly 200 pages of argument. BUT YOU TAKE PRIDE AT BEING TOTALLY STUPID!!
"PhysOrg scientific forums are totally dedicated to physics and technology..... If you need any help on your scientific problem or you want to ask a question related to physics or technology, then PhysOrg is the right place to be, since a lot of experts from various fields visit PhysOrg Forums every day."
So much for this forum.
A lot of experts, eh?
The place to come for help on a scientific problem, eh?
Let me rewrite the first line of the Illiac quote:
"I think that Atl5p, Fargo and Illiac (plus a few unidentified Guests)" are so full of sh*t its un-f**k**g-believable.
How can they be on a Physics forum?
How?
They make no attempt to understand anyones argument.
Show no capacity for rational thought.
Illiac your " two possible interpretations" are a joke.
Read some of the will fly posts and WEEP.
I think that Atl5p, Fargo and I (plus a few unidentified Guests) long ago agreed that there were two possible interpretations. EH?
1. Speed of the plane is measured as movement forward from a stationary observer. This interpretation totally discounts any effect from the belt because it already says that the plane is moving forward away from a stationary observer and hence all actions of the belt must be netted out for that to occur. If that is your definition, then of course the problem is trivial and the plane will fly. WHAT???
2. Speed of the plane is measured relative to the belt, just like you see on a treadmill in a gym a millions of times per day. The plane moves forward relative to the belt in one direction and the belt moves in the opposite direction at the same speed and the plane is stationary with respect to an outside observer, thus no airspeed and it will not fly. WHAT???
The problem here has been a total refusal of the "it will fly" folks to acknowledge the second interpretation which has been muddled by all sorts of "new physics" such as "free wheeling", to support their claim that even if you did interpret the problem as case #2, the plane still would fly because there's nothing the conveyor could do to stop the forward motion of the plane. Now it seems that while there be some acknowledgment that #2 is possible, they want to argue that #1 is a "more correct interpretation" or even more amazing, that you couldn't build a controller to work for case #2 so therefore #1 has to be the only possible interpretation...incredible!! WHAT??? Now I am reading a post that suggests that you might be able to get a close match of speeds but that the plane would inch forward every so slightly so therefore it would always have the advantage over the belt....give me a break!! WHAT??? Certainly, you could just put a light sensor at the side of the conveyor about an inch ahead of the plane's wheel and when the wheel triggers the light, speed up the conveyor until the sensor goes out and with some smoothing intellegence the whole thing could probably match speeds within +- a couple inches/sec....that's not close enough?? WHAT???
Remember that the it will fly folks have to own up to a long history of posts about "free wheeling" which has been used both to support their case for interpretation #1 and also to refute all possibility of interpretation #2. WHAT??? I think that a new thread should be started on that topic alone just to capture the madness in one place.
I also think it has been interesting to note the difference in civility between the "it will fly" posters versus the "no fly" posters...wonder why that is? BECAUSE YOU TAKE PRIDE AT BEING STUPID!! Alt5p has born the brunt of this because he's obviously put a LOT more energy into this debate but has for the most part (OK, one bad night) been extremely patient and civil. WHAT???
Certainly this has been an interesting problem and a demonstration that any "learning" by web board is probably a futile effort as I don't see anyone changing their original stance on the problem after nearly 200 pages of argument. BUT YOU TAKE PRIDE AT BEING TOTALLY STUPID!!
"PhysOrg scientific forums are totally dedicated to physics and technology..... If you need any help on your scientific problem or you want to ask a question related to physics or technology, then PhysOrg is the right place to be, since a lot of experts from various fields visit PhysOrg Forums every day."
So much for this forum.
A lot of experts, eh?
The place to come for help on a scientific problem, eh?
Let me rewrite the first line of the Illiac quote:
"I think that Atl5p, Fargo and Illiac (plus a few unidentified Guests)" are so full of sh*t its un-f**k**g-believable.
How can they be on a Physics forum?
How?
They make no attempt to understand anyones argument.
Show no capacity for rational thought.
Illiac your " two possible interpretations" are a joke.
Read some of the will fly posts and WEEP.
I'll take full credit for the dipshits I,II,III & IV! Why because they fit my definition of dipshits!
What is my definition you might ask...
A person who:
1) Argues a point from ignorance (not personal but knowledge).
2) Does not have the critical thinking skills necessary to formulate a scientific answer to the problem they are arguing.
(1 & 2 are normal for all of us prior to our education!)
3) Ignores or refutes polite attempts to correct points 1 & 2.
and most importantly.
4) Over and over telling people on this list (full of people with physics degrees, including myself), That _they_ are ignorant of the parameters of the problem when it is very obvious that they are uninformed as to the the physics involved.
Krreagan
What is my definition you might ask...
A person who:
1) Argues a point from ignorance (not personal but knowledge).
2) Does not have the critical thinking skills necessary to formulate a scientific answer to the problem they are arguing.
(1 & 2 are normal for all of us prior to our education!)
3) Ignores or refutes polite attempts to correct points 1 & 2.
and most importantly.
4) Over and over telling people on this list (full of people with physics degrees, including myself), That _they_ are ignorant of the parameters of the problem when it is very obvious that they are uninformed as to the the physics involved.
Krreagan
QUOTE (WHAT???+Dec 22 2005, 10:24 PM)
BUT YOU TAKE PRIDE AT BEING TOTALLY STUPID!!
You pointed out that this a a physics forum so that's some really excellent physics there WHAT???
QUOTE (WHAT???+Dec 22 2005, 10:24 PM)
Let me rewrite the first line of the Illiac quote:
"I think that Atl5p, Fargo and Illiac (plus a few unidentified Guests)" are so full of sh*t its un-f**k**g-believable.
"I think that Atl5p, Fargo and Illiac (plus a few unidentified Guests)" are so full of sh*t its un-f**k**g-believable.
More outstanding physics there WHATT???
You couldn't better illustrate my point about lack of civility. More irrelevant bashing in lieu of substance.
You couldn't better illustrate my point about lack of civility. More irrelevant bashing in lieu of substance.
QUOTE (Bloy+Dec 22 2005, 10:19 PM)
QUOTE (Illiac+Dec 22 2005, 09:57 PM)
QUOTE (sooks+Dec 22 2005, 07:45 PM)
A lot more "Civility" ........??? Clearly, you missed the part where Atl snapped on me. I mean he lost it..... I know you guys did take it harshly from some before. But it was pretty much unprovoked, i hadnt done any name calling, just simply proving his ideas wrong with the physics.
Atl5p acknowledge that and took the time to appologize. Try to look at the context of the forum at that time with some of your "thought companions" bashing all the no fly guys/gals with I,II,III,IV-type labels which you'll find easy to trace.
Atl5p acknowledge that and took the time to appologize. Try to look at the context of the forum at that time with some of your "thought companions" bashing all the no fly guys/gals with I,II,III,IV-type labels which you'll find easy to trace.
QUOTE (sooks+Dec 22 2005, 07:45 PM)
I dont think most of the will fly guys care much about situation 1 or 2..... whether you use belt or ground...just as long as your consistent with both of them. The main problem most of you no flyers were using is that you had 2 different refernce frames...which is the case where it doesnt work...
But there are two different reference frames. One (the conveyor)determines the speed that the plane is moving down the conveyor and is used in #2 to match the conveyor speed. The other, the outside world is where "apparent motion" (despite the fact that plane may be moving quite fast down the conveyor) determines whether you have airpseed or not. Please refer to any 1st semester college physics class in mechanics and look at problems considering relative motion where one object is moving on the surface of another object, whether the surface is a solid or a fluid. Also, if there are pilots in this debate, surely they must be aware that two reference frames are used ALL THE TIME when considering flight in a moving airmass. Winds aloft give the the speed that an airmass is moving with respect to the ground. Your airspeed in that airmass tells you speed with respect to the airmass. Net the two, with consideration to vectors and you get ground speed...pilots do this everyday...the airmass is like the conveyor, the plane moves within it and the airmass moves in relation to the ground.This problem should be simpler as the vector calculation is trivial. For the life of me, I don't see why pilots of all people in this thread have difficulty accepting that perspective. BTW, what's your groundspeed if you are flying 70kts directly into a headwind of 70kts? Are you moving? Got a lot of fuel?
And, i dont know how you say a LOT more effort into it. THere are plenty of the will fly group (me included) that has spent a lot of time doing some research and running the formulas, using examples, everything to show the physics of it. just to have it thrown out the window and not even acknowledged, but in turn a rsponse comes back that just twists it around another way. I believe thats why you no flyers recieved so much flak is because it was like pulling teeth to get a straight answer. It was amazing how factual information could just be completely ignored. I didnt care if you debated it, or showed it wrong... There was so many times it was just flat out ignored. It starts to get out at people when they spend all that time coming up with a thought out rational explanation, and dont recieve anything back, except for twisting around what they said to something completely the opposite.
QUOTE (sooks+Dec 22 2005, 07:45 PM)
And, i dont know how you say a LOT more effort into it. THere are plenty of the will fly group (me included) that has spent a lot of time doing some research and running the formulas, using examples, everything to show the physics of it. just to have it thrown out the window and not even acknowledged, but in turn a rsponse comes back that just twists it around another way. I believe thats why you no flyers recieved so much flak is because it was like pulling teeth to get a straight answer. It was amazing how factual information could just be completely ignored. I didnt care if you debated it, or showed it wrong... There was so many times it was just flat out ignored. It starts to get out at people when they spend all that time coming up with a thought out rational explanation, and dont recieve anything back, except for twisting around what they said to something completely the opposite.
Sorry, that was not clear on my part, I meant effort relative to other no-fly posters. Face it, Atl5p tried to keep up with all your posts and I can't imagine how much time that took. For a problem who's solution depends only upon "speed", (the only givens in the problem) I think Atl5p certainly went the the distance in trying to accomodate all the challenges into turf such as CRF, total force to move a 747, you name it. You didn't see me respond to all that stuff as I certainly have other things to do and felt it more important to focus on relative motion...beating a dead horse.
okay, now bring that 70kts down to the conveyor....
Is the conveyor moving? NO. Because there is no forward motion of the plane..
This is a similar situation when AI was at the EAA convention in Oshkosh(several times)....
When the wind storm came in, all the ultra-light pilots ran to their planes. we were just beyond a tall hedge. The planes took off practically vertically, needing only a small movment along the runway. we couldn't actually see them lift off, but they sounded like a bunch of bumble bees buzzing up into the air..
let me add to my own reply above...
regardless that the plane is in an air mass, the air mass is still referenced to the ground. You are still in the same reference frame(the ground) and the conveyor will stop if the plane isn't moving forward....as you imply by the 70kt headwind.
Ruling out ground effect, you should be able to land that plane vertically over a motionless conveyor. You could even power down causing the wind to move you backward and the conveyour would slip under the wheels in reverse(forward) following the opposite movement condition.....you just better have very good control as the "now touching" wheels will tend to follow the conveyor friction if not perfectly straight.
okay, now bring that 70kts down to the conveyor....
Is the conveyor moving? NO. Because there is no forward motion of the plane..
This is a similar situation when AI was at the EAA convention in Oshkosh(several times)....
When the wind storm came in, all the ultra-light pilots ran to their planes. we were just beyond a tall hedge. The planes took off practically vertically, needing only a small movment along the runway. we couldn't actually see them lift off, but they sounded like a bunch of bumble bees buzzing up into the air..
let me add to my own reply above...
regardless that the plane is in an air mass, the air mass is still referenced to the ground. You are still in the same reference frame(the ground) and the conveyor will stop if the plane isn't moving forward....as you imply by the 70kt headwind.
Ruling out ground effect, you should be able to land that plane vertically over a motionless conveyor. You could even power down causing the wind to move you backward and the conveyour would slip under the wheels in reverse(forward) following the opposite movement condition.....you just better have very good control as the "now touching" wheels will tend to follow the conveyor friction if not perfectly straight.
I vote FLY of course!
QUOTE (Bloy+Dec 22 2005, 10:46 PM)
okay, now bring that 70kts down to the conveyor....
Is the conveyor moving? NO. Because there is no forward motion of the plane..
This is a similar situation when AI was at the EAA convention in Oshkosh(several times)....
When the wind storm came in, all the ultra-light pilots ran to their planes. we were just beyond a tall hedge. The planes took off practically vertically, needing only a small movment along the runway. we couldn't actually see them lift off, but they sounded like a bunch of bumble bees buzzing up into the air..
I'm afraid you lost me on that one Bloy. The fact that the ultralights took so little runway should emphasize that the relative wind was already near their rotation speed. If was just slightly more, they could have taken off and had a near zero groundspeed...the whole point of the plane stationary on the conveyor despite moving fast down the conveyor. Probably not all that safe for the ultralights to do in any case.
Is the conveyor moving? NO. Because there is no forward motion of the plane..
This is a similar situation when AI was at the EAA convention in Oshkosh(several times)....
When the wind storm came in, all the ultra-light pilots ran to their planes. we were just beyond a tall hedge. The planes took off practically vertically, needing only a small movment along the runway. we couldn't actually see them lift off, but they sounded like a bunch of bumble bees buzzing up into the air..
I'm afraid you lost me on that one Bloy. The fact that the ultralights took so little runway should emphasize that the relative wind was already near their rotation speed. If was just slightly more, they could have taken off and had a near zero groundspeed...the whole point of the plane stationary on the conveyor despite moving fast down the conveyor. Probably not all that safe for the ultralights to do in any case.
QUOTE (Bloy+Dec 22 2005, 10:46 PM)
let me add to my own reply above...
regardless that the plane is in an air mass, I said that the air mass is still referenced to the ground. I said that too You are still in the same reference frame(the ground) and the conveyor will stop if the plane isn't moving forward....as you imply by the 70kt headwind.I have no idea what you mean here Bloy. The point is that you have 70kts airspeed but are stationary with respect to the ground, hence groundspeed =0. The analogy being that you can appear to be motionless with respect to the outside observer even though you are moving through the airmass at 70kts because the airmass is also moving at an equal but opposite speed, just like the conveyor problem. Hence substitute the airmass for the conveyor and you are looking at the problem in exactly the same fashion with respect to multiple reference frames...and since the speeds match, the plane is motionless (wrt outside) despite moving quite rapidly down the conveyor.
Ruling out ground effect, you should be able to land that plane vertically over a motionless conveyor.
regardless that the plane is in an air mass, I said that the air mass is still referenced to the ground. I said that too You are still in the same reference frame(the ground) and the conveyor will stop if the plane isn't moving forward....as you imply by the 70kt headwind.I have no idea what you mean here Bloy. The point is that you have 70kts airspeed but are stationary with respect to the ground, hence groundspeed =0. The analogy being that you can appear to be motionless with respect to the outside observer even though you are moving through the airmass at 70kts because the airmass is also moving at an equal but opposite speed, just like the conveyor problem. Hence substitute the airmass for the conveyor and you are looking at the problem in exactly the same fashion with respect to multiple reference frames...and since the speeds match, the plane is motionless (wrt outside) despite moving quite rapidly down the conveyor.
Ruling out ground effect, you should be able to land that plane vertically over a motionless conveyor.
QUOTE (Illiac+Dec 22 2005, 10:46 PM)
QUOTE (WHAT???+Dec 22 2005, 10:24 PM)
BUT YOU TAKE PRIDE AT BEING TOTALLY STUPID!!
You pointed out that this a a physics forum so that's some really excellent physics there WHAT???
QUOTE (WHAT???+Dec 22 2005, 10:24 PM)
Let me rewrite the first line of the Illiac quote:
"I think that Atl5p, Fargo and Illiac (plus a few unidentified Guests)" are so full of sh*t its un-f**k**g-believable.
"I think that Atl5p, Fargo and Illiac (plus a few unidentified Guests)" are so full of sh*t its un-f**k**g-believable.
More outstanding physics there WHATT???
You couldn't better illustrate my point about lack of civility. More irrelevant bashing in lieu of substance.
Don't be such a stuck up so and so. "Holier than thou" - dont make me laugh.
From past evidence you wouldn't recognize excellent or outstanding physics if it hit you in the face with a baseball bat.
How about your lack of civility? You think you can go on day after day insulting everyones intelligence by endlessly repeating moronic arguments?
Your crassly stupid statements are the equivalent of intellectual mud wrestling. Most of the will fly guys are trying to discuss the issue using physics, maths, logic. Lofty aspirations maybe? But you respond with gravity defying, cretinous, idiocy on every occasion.
I couldn't have put it better myself: a recent article in Journal of Personality and Social Psychology
Unskilled and Unaware of It: How Difficulties in Recognizing One's Own Incompetence Lead to Inflated Self-Assessments
Justin Kruger and David Dunning
Department of Psychology
Cornell University
Abstract
People tend to hold overly favorable views of their abilities in many social and intellectual domains. The authors suggest that this overestimation occurs, in part, because people who are unskilled in these domains suffer a dual burden: Not only do these people reach erroneous conclusions and make unfortunate choices, but their incompetence robs them of the metacognitive ability to realize it. Across 4 studies, the authors found that participants scoring in the bottom quartile on tests of humor, grammar, and logic grossly overestimated their test performance and ability. Although their test scores put them in the 12th percentile, they estimated themselves to be in the 62nd. Several analyses linked this miscalibration to deficits in metacognitive skill, or the capacity to distinguish accuracy from error. Paradoxically, improving the skills of participants, and thus increasing their metacognitive competence, helped them recognize the limitations of their abilities.
What is a guy to do faced with constantly self satisfied dummkopfs* like you?
*dummkopf
NOUN: A mentally dull person: blockhead, chump, clod, dolt, dullard, dummy, dunce, numskull, thickhead. Slang : dimwit, dumbbell, dumbo.
You couldn't better illustrate my point about lack of civility. More irrelevant bashing in lieu of substance.
Don't be such a stuck up so and so. "Holier than thou" - dont make me laugh.
From past evidence you wouldn't recognize excellent or outstanding physics if it hit you in the face with a baseball bat.
How about your lack of civility? You think you can go on day after day insulting everyones intelligence by endlessly repeating moronic arguments?
Your crassly stupid statements are the equivalent of intellectual mud wrestling. Most of the will fly guys are trying to discuss the issue using physics, maths, logic. Lofty aspirations maybe? But you respond with gravity defying, cretinous, idiocy on every occasion.
I couldn't have put it better myself: a recent article in Journal of Personality and Social Psychology
Unskilled and Unaware of It: How Difficulties in Recognizing One's Own Incompetence Lead to Inflated Self-Assessments
Justin Kruger and David Dunning
Department of Psychology
Cornell University
Abstract
People tend to hold overly favorable views of their abilities in many social and intellectual domains. The authors suggest that this overestimation occurs, in part, because people who are unskilled in these domains suffer a dual burden: Not only do these people reach erroneous conclusions and make unfortunate choices, but their incompetence robs them of the metacognitive ability to realize it. Across 4 studies, the authors found that participants scoring in the bottom quartile on tests of humor, grammar, and logic grossly overestimated their test performance and ability. Although their test scores put them in the 12th percentile, they estimated themselves to be in the 62nd. Several analyses linked this miscalibration to deficits in metacognitive skill, or the capacity to distinguish accuracy from error. Paradoxically, improving the skills of participants, and thus increasing their metacognitive competence, helped them recognize the limitations of their abilities.
What is a guy to do faced with constantly self satisfied dummkopfs* like you?
*dummkopf
NOUN: A mentally dull person: blockhead, chump, clod, dolt, dullard, dummy, dunce, numskull, thickhead. Slang : dimwit, dumbbell, dumbo.
I have not read this entire thread but I can't believe that it is still going.
The plane cannot take off, there is no airspeed over the wings to provide lift!
The conveyor might produce some air movement and a propeller will blow some air past the wing but the propeller does not make a plane go up because it moves air over the wing. It allows the plane to lift off because it moves the wing through the air by moving the entire plane forward.
In this senario the plane is not moving at all relative to the air therefore no airflow over the wing therefore no liftoff. All you are doing is moving the plane forward to keep it in place relative to the air.
This assumes a calm day.
If there is a 100 mph wind then even some tethered craft will attempt to lift off since air is in fact moving over the wing. This is why small aircraft do get tied down when not in use.
The plane cannot take off, there is no airspeed over the wings to provide lift!
The conveyor might produce some air movement and a propeller will blow some air past the wing but the propeller does not make a plane go up because it moves air over the wing. It allows the plane to lift off because it moves the wing through the air by moving the entire plane forward.
In this senario the plane is not moving at all relative to the air therefore no airflow over the wing therefore no liftoff. All you are doing is moving the plane forward to keep it in place relative to the air.
This assumes a calm day.
If there is a 100 mph wind then even some tethered craft will attempt to lift off since air is in fact moving over the wing. This is why small aircraft do get tied down when not in use.
here's another one for the contenders on this thread.
In movies such as "The Italian Job" a car is driven up into a moving trailer or van.
When the drive wheels get on the ramp does the driver of the car have to immediatly slow down by hitting the brakes hard or not,,, and why?
In movies such as "The Italian Job" a car is driven up into a moving trailer or van.
When the drive wheels get on the ramp does the driver of the car have to immediatly slow down by hitting the brakes hard or not,,, and why?
No Fly of course
QUOTE (Illiac+Dec 22 2005, 11:10 PM)
QUOTE (Bloy+Dec 22 2005, 10:46 PM)
okay, now bring that 70kts down to the conveyor....
..
I'm afraid you lost me on that one Bloy. The fact that....
..
I'm afraid you lost me on that one Bloy. The fact that....
QUOTE (Bloy+Dec 22 2005, 10:46 PM)
let me add to my own reply above....
Ha - Bloy's lost you? Youve been lost up thick-as-sh*t creek for a long time now.
Need a paddle to find your way back to civilisation?
Get in touch with the Cornell guys before it's too late
Go and read again the posts by Krreagan for example. They contain substance. They contain physics... in lieu of your idiocy.
Ha - Bloy's lost you? Youve been lost up thick-as-sh*t creek for a long time now.
Need a paddle to find your way back to civilisation?
Get in touch with the Cornell guys before it's too late
Go and read again the posts by Krreagan for example. They contain substance. They contain physics... in lieu of your idiocy.
QUOTE (yesitdid+Dec 22 2005, 11:37 PM)
I have not read this entire thread but I can't believe that it is still going.
The plane cannot take off, there is no airspeed over the wings to provide lift!
The conveyor might produce some air movement and a propeller will blow some air past the wing but the propeller does not make a plane go up because it moves air over the wing. It allows the plane to lift off because it moves the wing through the air by moving the entire plane forward.
In this senario the plane is not moving at all relative to the air therefore no airflow over the wing therefore no liftoff. All you are doing is moving the plane forward to keep it in place relative to the air.
This assumes a calm day.
If there is a 100 mph wind then even some tethered craft will attempt to lift off since air is in fact moving over the wing. This is why small aircraft do get tied down when not in use.
I rest my case..... AAAAAAAAAAAAAAAAAAARRRRGGHHHHHHH
The plane cannot take off, there is no airspeed over the wings to provide lift!
The conveyor might produce some air movement and a propeller will blow some air past the wing but the propeller does not make a plane go up because it moves air over the wing. It allows the plane to lift off because it moves the wing through the air by moving the entire plane forward.
In this senario the plane is not moving at all relative to the air therefore no airflow over the wing therefore no liftoff. All you are doing is moving the plane forward to keep it in place relative to the air.
This assumes a calm day.
If there is a 100 mph wind then even some tethered craft will attempt to lift off since air is in fact moving over the wing. This is why small aircraft do get tied down when not in use.
I rest my case..... AAAAAAAAAAAAAAAAAAARRRRGGHHHHHHH
QUOTE (SkiSTX+Dec 22 2005, 04:01 PM)
re: the car.
There are obviously 2 trains of thought here. And it has to do with how the phrase "moves forward" is interpreted. You can either take it to mean in relation to the belt or in relation to the tower/ground/calm air.
1--
If the 'speed' of the two objects is measured by radar guns from the tower which have to match each other at all times, then the car will achieve wind flow over it's wings. And the speeds could be as follows...
car radar speed = 50
belt radar speed = 50
wheel speed/car speedometer = 100
air speed over wings = 50
2--
If the 'speed' of the two objects is measured based on their own speedometers which have to match each other at all times, then the car will have zero wind over it's wings. And the speeds could be as follows...
car speedometer speed = 50
belt speedometer speed = 50
wheel speed/car speedometer = 50
air speed over wings = 0
--
So neither side is right or wrong... just a different interpretation of the question which doesn't explicitly state what 'moves forward' really means.
However, in scenario 2, the speedometer of the car is measuring it's speed in relation to the belt, and the belt is measuring it's speed in relation to the dirt beneath it. Is this wrong? Not necessarily, but I think it would be more correct/scientific to measure both speeds in relation to the same object as per scenario 1.
So I will agree to disagree with the 'car no flyiers'.
BTW I don't mean to put words in anyones mouth... this is just the way I am interpreting the two sides of the argument.
So obviously, it's impossible for the treadbelt to stop the car either....the car MOVES from our vantage point standing next to a stationary molecule of air.
ANd a runner will move too....it is impossible for either to be held back by the treadmill, as long as the treadbelt's speed matches the speed of the object MOVING away from a fixed location on terra firma
that's what we've been trying to say all along, it's just been polluted with all the freewheeling this and driven wheels that ad nausium...it's really a stupid thing to argue about:
which weighs more, a pound of feathers or a pound of lead, it's just that simple....which side of the boarder to bury the survivors....the plane moves, the car moves, the runner moves, they all MUST move to satisfy the question.
the plane will obviously move, this isn't a question about force from the treadbelt, the treadbelt dosn't have anything to do with nothing.
There are obviously 2 trains of thought here. And it has to do with how the phrase "moves forward" is interpreted. You can either take it to mean in relation to the belt or in relation to the tower/ground/calm air.
1--
If the 'speed' of the two objects is measured by radar guns from the tower which have to match each other at all times, then the car will achieve wind flow over it's wings. And the speeds could be as follows...
car radar speed = 50
belt radar speed = 50
wheel speed/car speedometer = 100
air speed over wings = 50
2--
If the 'speed' of the two objects is measured based on their own speedometers which have to match each other at all times, then the car will have zero wind over it's wings. And the speeds could be as follows...
car speedometer speed = 50
belt speedometer speed = 50
wheel speed/car speedometer = 50
air speed over wings = 0
--
So neither side is right or wrong... just a different interpretation of the question which doesn't explicitly state what 'moves forward' really means.
However, in scenario 2, the speedometer of the car is measuring it's speed in relation to the belt, and the belt is measuring it's speed in relation to the dirt beneath it. Is this wrong? Not necessarily, but I think it would be more correct/scientific to measure both speeds in relation to the same object as per scenario 1.
So I will agree to disagree with the 'car no flyiers'.
BTW I don't mean to put words in anyones mouth... this is just the way I am interpreting the two sides of the argument.
So obviously, it's impossible for the treadbelt to stop the car either....the car MOVES from our vantage point standing next to a stationary molecule of air.
ANd a runner will move too....it is impossible for either to be held back by the treadmill, as long as the treadbelt's speed matches the speed of the object MOVING away from a fixed location on terra firma
that's what we've been trying to say all along, it's just been polluted with all the freewheeling this and driven wheels that ad nausium...it's really a stupid thing to argue about:
which weighs more, a pound of feathers or a pound of lead, it's just that simple....which side of the boarder to bury the survivors....the plane moves, the car moves, the runner moves, they all MUST move to satisfy the question.
the plane will obviously move, this isn't a question about force from the treadbelt, the treadbelt dosn't have anything to do with nothing.
QUOTE (Bloy+Dec 22 2005, 03:28 PM)
QUOTE (fargo boyle+Dec 22 2005, 03:22 PM)
QUOTE (Bloy+Dec 22 2005, 03:00 PM)
I think you will find you will be moving...according to your pedometer attached to your belt(EDIT- BODY or personal belt, ).... at 1 mph to match the speed of the conveyor and satisfy the problem. which translates to the same speed of .5mph of the belt....calibrated to what the belt is sitting upon....a common reference.
This is the part where you're wrong. Because you're not trying to match your speed to the belt. The belt is matching it's speed to you!
YOU have to move first in order for the belt to move!
So let's do this in slow motion: you move forward slowly and travel a distance of 1 inch in 1 second in relation to a standing observer next to the treadmill. Now the treadmill makes it's first read of the sensors. What speed are you travelling at? 1 inch per second. So that's what the treadmill set it's speed to, in relation to the standing observer. 1 inch per second.
Yes,, and while the belt is moving opposite that 1 unit per second, you are moving another 2unit per second while the belt is making its initial move.... so you don't suddenly go backwards with the belt. you progress! You have to apply more power to your legs, wheels, propeller to continue your forward movement of 1 unit per second.... that is why your speedometer(on the car) will be reading twice the speed of what you are actually traveling.
A plane just applies full power all at once and gradually accelerates as its mass adjusts because its wheels are not so dependant.
..also according to your scenario, the belt(conveyor) wouldn't move because when it takes its reading, you have already moved that 1 unit and the reading would be 0units per sec(at the time of the reading) . Now if you are in a state of continuous motion, THEN the belt would take that first reading and move.
It is obvious that it is clearly impossible for a treadmill to cause a man to appear to be 'running in place'. That's impossible, and that's all there is to it, PERIOD.
That's why treadmills were such a fad in the 80's, until they found out that people really didn't burn any calories while training on one...it was the same as hanging from a bar, and wiggling your legs...no WORK got done, thus no ENERGY was burned....energy can never be destroyed.
So obviously, it's impossible for the treadbelt to stop the car either....the car MOVES from our vantage point standing next to a stationary molecule of air. I LOVE IT!!
ANd a runner will move too....it is impossible for either to be held back by the treadmill, as long as the treadbelt's speed matches the speed of the object MOVING away from a fixed location on terra firma
that's what we've been trying to say all along, OF COURSE YOU HAVE!! it's just been polluted with all the freewheeling this and driven wheels that ad nausium...it's really a stupid thing to argue about:
which weighs more, a pound of feathers or a pound of lead, it's just that simple....which side of the boarder to bury the survivors....the plane moves, the car moves, the runner moves, they all MUST move to satisfy the question.
the plane will obviously move, this isn't a question about force from the treadbelt, the treadbelt dosn't have anything to do with nothing.
More irrelevant STUPIDITY in lieu of substance.
Are you on the wrong forum by any chance? Try the "I have my head stuck up my ***" forum.
While your up there have a look for Illiac and atl5p.
This is the part where you're wrong. Because you're not trying to match your speed to the belt. The belt is matching it's speed to you!
YOU have to move first in order for the belt to move!
So let's do this in slow motion: you move forward slowly and travel a distance of 1 inch in 1 second in relation to a standing observer next to the treadmill. Now the treadmill makes it's first read of the sensors. What speed are you travelling at? 1 inch per second. So that's what the treadmill set it's speed to, in relation to the standing observer. 1 inch per second.
Yes,, and while the belt is moving opposite that 1 unit per second, you are moving another 2unit per second while the belt is making its initial move.... so you don't suddenly go backwards with the belt. you progress! You have to apply more power to your legs, wheels, propeller to continue your forward movement of 1 unit per second.... that is why your speedometer(on the car) will be reading twice the speed of what you are actually traveling.
A plane just applies full power all at once and gradually accelerates as its mass adjusts because its wheels are not so dependant.
..also according to your scenario, the belt(conveyor) wouldn't move because when it takes its reading, you have already moved that 1 unit and the reading would be 0units per sec(at the time of the reading) . Now if you are in a state of continuous motion, THEN the belt would take that first reading and move.
It is obvious that it is clearly impossible for a treadmill to cause a man to appear to be 'running in place'. That's impossible, and that's all there is to it, PERIOD.
That's why treadmills were such a fad in the 80's, until they found out that people really didn't burn any calories while training on one...it was the same as hanging from a bar, and wiggling your legs...no WORK got done, thus no ENERGY was burned....energy can never be destroyed.
QUOTE (Guest+Dec 23 2005, 12:05 AM)
So obviously, it's impossible for the treadbelt to stop the car either....the car MOVES from our vantage point standing next to a stationary molecule of air. I LOVE IT!!
ANd a runner will move too....it is impossible for either to be held back by the treadmill, as long as the treadbelt's speed matches the speed of the object MOVING away from a fixed location on terra firma
that's what we've been trying to say all along, OF COURSE YOU HAVE!! it's just been polluted with all the freewheeling this and driven wheels that ad nausium...it's really a stupid thing to argue about:
which weighs more, a pound of feathers or a pound of lead, it's just that simple....which side of the boarder to bury the survivors....the plane moves, the car moves, the runner moves, they all MUST move to satisfy the question.
the plane will obviously move, this isn't a question about force from the treadbelt, the treadbelt dosn't have anything to do with nothing.
More irrelevant STUPIDITY in lieu of substance.
Are you on the wrong forum by any chance? Try the "I have my head stuck up my ***" forum.
While your up there have a look for Illiac and atl5p.
QUOTE (krreagan+Dec 22 2005, 08:24 PM)
QUOTE (Illiac+Dec 22 2005, 12:28 PM)
QUOTE (SkiSTX+Dec 22 2005, 04:01 PM)
re: the car.
There are obviously 2 trains of thought here. And it has to do with how the phrase "moves forward" is interpreted. You can either take it to mean in relation to the belt or in relation to the tower/ground/calm air.
1--
If the 'speed' of the two objects is measured by radar guns from the tower which have to match each other at all times, then the car will achieve wind flow over it's wings. And the speeds could be as follows...
car radar speed = 50
belt radar speed = 50
wheel speed/car speedometer = 100
air speed over wings = 50
2--
If the 'speed' of the two objects is measured based on their own speedometers which have to match each other at all times, then the car will have zero wind over it's wings. And the speeds could be as follows...
car speedometer speed = 50
belt speedometer speed = 50
wheel speed/car speedometer = 50
air speed over wings = 0
--
So neither side is right or wrong... just a different interpretation of the question which doesn't explicitly state what 'moves forward' really means.
However, in scenario 2, the speedometer of the car is measuring it's speed in relation to the belt, and the belt is measuring it's speed in relation to the dirt beneath it. Is this wrong? Not necessarily, but I think it would be more correct/scientific to measure both speeds in relation to the same object as per scenario 1.
So I will agree to disagree with the 'car no flyiers'.
BTW I don't mean to put words in anyones mouth... this is just the way I am interpreting the two sides of the argument.
SkiSTX,
I think that Atl5p, Fargo and I (plus a few unidentified Guests) long ago agreed that there were two possible interpretations.
1. Speed of the plane is measured as movement forward from a stationary observer. This interpretation totally discounts any effect from the belt because it already says that the plane is moving forward away from a stationary observer and hence all actions of the belt must be netted out for that to occur. If that is your definition, then of course the problem is trivial and the plane will fly.
2. Speed of the plane is measured relative to the belt, just like you see on a treadmill in a gym a millions of times per day. The plane moves forward relative to the belt in one direction and the belt moves in the opposite direction at the same speed and the plane is stationary with respect to an outside observer, thus no airspeed and it will not fly.
The problem here has been a total refusal of the "it will fly" folks to acknowledge the second interpretation which has been muddled by all sorts of "new physics" such as "free wheeling", to support their claim that even if you did interpret the problem as case #2, the plane still would fly because there's nothing the conveyor could do to stop the forward motion of the plane. Now it seems that while there be some acknowledgment that #2 is possible, they want to argue that #1 is a "more correct interpretation" or even more amazing, that you couldn't build a controller to work for case #2 so therefore #1 has to be the only possible interpretation...incredible!! Now I am reading a post that suggests that you might be able to get a close match of speeds but that the plane would inch forward every so slightly so therefore it would always have the advantage over the belt....give me a break!! Certainly, you could just put a light sensor at the side of the conveyor about an inch ahead of the plane's wheel and when the wheel triggers the light, speed up the conveyor until the sensor goes out and with some smoothing intellegence the whole thing could probably match speeds within +- a couple inches/sec....that's not close enough??
Remember that the it will fly folks have to own up to a long history of posts about "free wheeling" which has been used both to support their case for interpretation #1 and also to refute all possibility of interpretation #2. I think that a new thread should be started on that topic alone just to capture the madness in one place.
I also think it has been interesting to note the difference in civility between the "it will fly" posters versus the "no fly" posters...wonder why that is? Alt5p has born the brunt of this because he's obviously put a LOT more energy into this debate but has for the most part (OK, one bad night) been extremely patient and civil.
Certainly this has been an interesting problem and a demonstration that any "learning" by web board is probably a futile effort as I don't see anyone changing their original stance on the problem after nearly 200 pages of argument.
Looks like I'll have to do this again...
The second interpretation violates that original question!
"The plane moves in one direction, while the conveyer moves in the opposite direction."
This implies a single unified reference frame outside both the plane and belt (ie... The ground!) Interpreting it as measuring one in terms of the other is a non sequitur.
"This conveyer has a control system that tracks the plane speed and tunes the speed of the conveyer to be exactly the same (but in opposite direction)."
"but in opposite direction" implies that the belt is not instantaneous in its measurement and since a second reference frame is not given, then only one can be assumed, the ground reference frame is to be used to measure the speed of the plane. Not to mention that speed is defined as distance per unit time. If it is instantaneous time is zero and you have a divide by zero...and an infinite acceleration of the wheels. And they call our logic flawed!
The second interpretation violates that original question!
"The plane moves in one direction, while the conveyer moves in the opposite direction."
This implies a single unified reference frame outside both the plane and belt (ie... The ground!) Interpreting it as measuring one in terms of the other is a non sequitur.
"This conveyer has a control system that tracks the plane speed and tunes the speed of the conveyer to be exactly the same (but in opposite direction)."
"but in opposite direction" implies that the belt is not instantaneous in its measurement and since a second reference frame is not given, then only one can be assumed, the ground reference frame is to be used to measure the speed of the plane. Not to mention that speed is defined as distance per unit time. If it is instantaneous time is zero and you have a divide by zero...and an infinite acceleration of the wheels. And they call our logic flawed!
"new physics" such as "free wheeling"
New?? I think the wheel was invented at least ten thousand yeas ago! Not what I would call new! The term "free wheeling" refers to the fact that the brakes are not on! (Again, an extremely difficult concept to grasp) You can see that their interpretation is flawed!
The light sensor he mentions, tracks the planes position of the plane not speed... again violating the original conditions of the question.
He is also forgetting that for a very long time they interpreted the question as we did, and they were saying that the friction in the wheels coupled with the planes weight, would not allow the plane to move forward. ( pages in the 50's .. 90's )
Pounding our head against a wall... and beating a dead horse all come to mind!
It's been evident throughout that their knowledge of physics and physical concepts as well as critical thinking skills are all lacking! As a matter of fact, Atl5p has actually learned quite a bit. If you go back and read his early posts they were horrible! The later ones, although still flawed showed much improvement in terminology and understanding.
Krreagan
It's obvious that Atl5p learned a ton....
And it's also obvious that special k needs to choose his inturpretation.
See, he just said the car would move forward...
But just a couple of pages ago, he had this little gem:
http://forum.physorg.com/index.php?showtop...indpost&p=46905
But just a couple of pages ago, he had this little gem:
http://forum.physorg.com/index.php?showtop...indpost&p=46905
Okay, I've lurked in the darkness for a while and have two answers for you.
1) Conditions are idealized. The belt reacts instantaneously. Therefore the car does not move because the car can never gain the upper hand, as it were! This is like having a belt that is mass-less, frictionless and rotates freely.
2) Conditions are realistic. The belt can only detect the speed of the car after the speed has actually changed, therefore the car will creep forward as long as the car can maintain an acceleration! Once the wheels stop accelerating, the car will stop moving forward! As long as the belt has to play catchup, the car will always be moving slightly faster then the belt so it will move forward!
My US$.02
Krreagan
Somethings gotta give special K
The it is IMPOSSIBLE for the car to be held back by that conveyor...the question says it all, the object WILL MOVE!
There are obviously 2 trains of thought here. And it has to do with how the phrase "moves forward" is interpreted. You can either take it to mean in relation to the belt or in relation to the tower/ground/calm air.
1--
If the 'speed' of the two objects is measured by radar guns from the tower which have to match each other at all times, then the car will achieve wind flow over it's wings. And the speeds could be as follows...
car radar speed = 50
belt radar speed = 50
wheel speed/car speedometer = 100
air speed over wings = 50
2--
If the 'speed' of the two objects is measured based on their own speedometers which have to match each other at all times, then the car will have zero wind over it's wings. And the speeds could be as follows...
car speedometer speed = 50
belt speedometer speed = 50
wheel speed/car speedometer = 50
air speed over wings = 0
--
So neither side is right or wrong... just a different interpretation of the question which doesn't explicitly state what 'moves forward' really means.
However, in scenario 2, the speedometer of the car is measuring it's speed in relation to the belt, and the belt is measuring it's speed in relation to the dirt beneath it. Is this wrong? Not necessarily, but I think it would be more correct/scientific to measure both speeds in relation to the same object as per scenario 1.
So I will agree to disagree with the 'car no flyiers'.
BTW I don't mean to put words in anyones mouth... this is just the way I am interpreting the two sides of the argument.
SkiSTX,
I think that Atl5p, Fargo and I (plus a few unidentified Guests) long ago agreed that there were two possible interpretations.
1. Speed of the plane is measured as movement forward from a stationary observer. This interpretation totally discounts any effect from the belt because it already says that the plane is moving forward away from a stationary observer and hence all actions of the belt must be netted out for that to occur. If that is your definition, then of course the problem is trivial and the plane will fly.
2. Speed of the plane is measured relative to the belt, just like you see on a treadmill in a gym a millions of times per day. The plane moves forward relative to the belt in one direction and the belt moves in the opposite direction at the same speed and the plane is stationary with respect to an outside observer, thus no airspeed and it will not fly.
The problem here has been a total refusal of the "it will fly" folks to acknowledge the second interpretation which has been muddled by all sorts of "new physics" such as "free wheeling", to support their claim that even if you did interpret the problem as case #2, the plane still would fly because there's nothing the conveyor could do to stop the forward motion of the plane. Now it seems that while there be some acknowledgment that #2 is possible, they want to argue that #1 is a "more correct interpretation" or even more amazing, that you couldn't build a controller to work for case #2 so therefore #1 has to be the only possible interpretation...incredible!! Now I am reading a post that suggests that you might be able to get a close match of speeds but that the plane would inch forward every so slightly so therefore it would always have the advantage over the belt....give me a break!! Certainly, you could just put a light sensor at the side of the conveyor about an inch ahead of the plane's wheel and when the wheel triggers the light, speed up the conveyor until the sensor goes out and with some smoothing intellegence the whole thing could probably match speeds within +- a couple inches/sec....that's not close enough??
Remember that the it will fly folks have to own up to a long history of posts about "free wheeling" which has been used both to support their case for interpretation #1 and also to refute all possibility of interpretation #2. I think that a new thread should be started on that topic alone just to capture the madness in one place.
I also think it has been interesting to note the difference in civility between the "it will fly" posters versus the "no fly" posters...wonder why that is? Alt5p has born the brunt of this because he's obviously put a LOT more energy into this debate but has for the most part (OK, one bad night) been extremely patient and civil.
Certainly this has been an interesting problem and a demonstration that any "learning" by web board is probably a futile effort as I don't see anyone changing their original stance on the problem after nearly 200 pages of argument.
Looks like I'll have to do this again...
QUOTE
A plane is standing on runway that can move (some sort of band conveyer). The plane moves in one direction, while the conveyer moves in the opposite direction. This conveyer has a control system that tracks the plane speed and tunes the speed of the conveyer to be exactly the same (but in opposite direction).
The question is:
Will the plane take off or not? Will it be able to run up and take off?
The question is:
Will the plane take off or not? Will it be able to run up and take off?
The second interpretation violates that original question!
"The plane moves in one direction, while the conveyer moves in the opposite direction."
This implies a single unified reference frame outside both the plane and belt (ie... The ground!) Interpreting it as measuring one in terms of the other is a non sequitur.
"This conveyer has a control system that tracks the plane speed and tunes the speed of the conveyer to be exactly the same (but in opposite direction)."
"but in opposite direction" implies that the belt is not instantaneous in its measurement and since a second reference frame is not given, then only one can be assumed, the ground reference frame is to be used to measure the speed of the plane. Not to mention that speed is defined as distance per unit time. If it is instantaneous time is zero and you have a divide by zero...and an infinite acceleration of the wheels. And they call our logic flawed!
QUOTE (->
| QUOTE |
| A plane is standing on runway that can move (some sort of band conveyer). The plane moves in one direction, while the conveyer moves in the opposite direction. This conveyer has a control system that tracks the plane speed and tunes the speed of the conveyer to be exactly the same (but in opposite direction). The question is: Will the plane take off or not? Will it be able to run up and take off? |
The second interpretation violates that original question!
"The plane moves in one direction, while the conveyer moves in the opposite direction."
This implies a single unified reference frame outside both the plane and belt (ie... The ground!) Interpreting it as measuring one in terms of the other is a non sequitur.
"This conveyer has a control system that tracks the plane speed and tunes the speed of the conveyer to be exactly the same (but in opposite direction)."
"but in opposite direction" implies that the belt is not instantaneous in its measurement and since a second reference frame is not given, then only one can be assumed, the ground reference frame is to be used to measure the speed of the plane. Not to mention that speed is defined as distance per unit time. If it is instantaneous time is zero and you have a divide by zero...and an infinite acceleration of the wheels. And they call our logic flawed!
"new physics" such as "free wheeling"
New?? I think the wheel was invented at least ten thousand yeas ago! Not what I would call new! The term "free wheeling" refers to the fact that the brakes are not on! (Again, an extremely difficult concept to grasp) You can see that their interpretation is flawed!
The light sensor he mentions, tracks the planes position of the plane not speed... again violating the original conditions of the question.
He is also forgetting that for a very long time they interpreted the question as we did, and they were saying that the friction in the wheels coupled with the planes weight, would not allow the plane to move forward.
( pages in the 50's .. 90's )Pounding our head against a wall... and beating a dead horse all come to mind!
It's been evident throughout that their knowledge of physics and physical concepts as well as critical thinking skills are all lacking! As a matter of fact, Atl5p has actually learned quite a bit. If you go back and read his early posts they were horrible! The later ones, although still flawed showed much improvement in terminology and understanding.
Krreagan
It's obvious that Atl5p learned a ton....
And it's also obvious that special k needs to choose his inturpretation.
See, he just said the car would move forward...
QUOTE
"The plane moves in one direction, while the conveyer moves in the opposite direction."
This implies a single unified reference frame outside both the plane and belt (ie... The ground!) Interpreting it as measuring one in terms of the other is a non sequitur.
This implies a single unified reference frame outside both the plane and belt (ie... The ground!) Interpreting it as measuring one in terms of the other is a non sequitur.
But just a couple of pages ago, he had this little gem:
http://forum.physorg.com/index.php?showtop...indpost&p=46905
QUOTE (->
| QUOTE |
| "The plane moves in one direction, while the conveyer moves in the opposite direction." This implies a single unified reference frame outside both the plane and belt (ie... The ground!) Interpreting it as measuring one in terms of the other is a non sequitur. |
But just a couple of pages ago, he had this little gem:
http://forum.physorg.com/index.php?showtop...indpost&p=46905
Okay, I've lurked in the darkness for a while and have two answers for you.
1) Conditions are idealized. The belt reacts instantaneously. Therefore the car does not move because the car can never gain the upper hand, as it were! This is like having a belt that is mass-less, frictionless and rotates freely.
2) Conditions are realistic. The belt can only detect the speed of the car after the speed has actually changed, therefore the car will creep forward as long as the car can maintain an acceleration! Once the wheels stop accelerating, the car will stop moving forward! As long as the belt has to play catchup, the car will always be moving slightly faster then the belt so it will move forward!
My US$.02
Krreagan
Somethings gotta give special K
The it is IMPOSSIBLE for the car to be held back by that conveyor...the question says it all, the object WILL MOVE!
QUOTE (sooks+Dec 22 2005, 04:44 AM)
QUOTE (Fynlcut+Dec 22 2005, 01:26 AM)
I see it as the car NOT moving in relation to a fixed point. Simply because when I think of a car's speed it's related to the speedo. The wheels will not spin faster than the engine makes them.
A plane's engine acting on the air will pull the plane simply because the wheels will serve their purpose even a double the revolutions of a normal take off. (at least I'd hope.
I agree it just depends on how you measure the speed of a car. The plane, the way I see it doesn't matter because of it acting on the air for propulsion.
Id have to say im with fnylcut and flanker on this one. i like fnylcuts explanation on how you view this... That is similar to what i see with it too. Its actually a different FBD witha car then a plane. the force to move forward is transported through the wheels.
the example where its driving down the regular road and its going 50 and then you hit the conveyor going backwards... it wont simply doubling the speed.within the wheels.....if you didnt change the throttle speed....the wheels wouldnt accelerate any faster...the car would slow down. the wheels now wouldnt be able to gain any ground
Who gave you two permission to break special K's rules about using a fixed point?!?
You dipshits X and XI
A plane's engine acting on the air will pull the plane simply because the wheels will serve their purpose even a double the revolutions of a normal take off. (at least I'd hope.
I agree it just depends on how you measure the speed of a car. The plane, the way I see it doesn't matter because of it acting on the air for propulsion.
Id have to say im with fnylcut and flanker on this one. i like fnylcuts explanation on how you view this... That is similar to what i see with it too. Its actually a different FBD witha car then a plane. the force to move forward is transported through the wheels.
the example where its driving down the regular road and its going 50 and then you hit the conveyor going backwards... it wont simply doubling the speed.within the wheels.....if you didnt change the throttle speed....the wheels wouldnt accelerate any faster...the car would slow down. the wheels now wouldnt be able to gain any ground
Who gave you two permission to break special K's rules about using a fixed point?!?
You dipshits X and XI
QUOTE (sooks+Dec 22 2005, 05:42 AM)
QUOTE (krreagan+Dec 22 2005, 05:16 AM)
Okay, I've lurked in the darkness for a while and have two answers for you.
1) Conditions are idealized. The belt reacts instantaneously. Therefore the car does not move because the car can never gain the upper hand, as it were! This is like having a belt that is mass-less, frictionless and rotates freely.
2) Conditions are realistic. The belt can only detect the speed of the car after the speed has actually changed, therefore the car will creep forward as long as the car can maintain an acceleration! Once the wheels stop accelerating, the car will stop moving forward! As long as the belt has to play catchup, the car will always be moving slightly faster then the belt so it will move forward!
My US$.02
Krreagan
perfect explanation krregan.!!!
OMG!!! Get your mouth off of that sooks!!!
special K, put that thing back into your pants!!!
1) Conditions are idealized. The belt reacts instantaneously. Therefore the car does not move because the car can never gain the upper hand, as it were! This is like having a belt that is mass-less, frictionless and rotates freely.
2) Conditions are realistic. The belt can only detect the speed of the car after the speed has actually changed, therefore the car will creep forward as long as the car can maintain an acceleration! Once the wheels stop accelerating, the car will stop moving forward! As long as the belt has to play catchup, the car will always be moving slightly faster then the belt so it will move forward!
My US$.02
Krreagan
perfect explanation krregan.!!!
OMG!!! Get your mouth off of that sooks!!!
special K, put that thing back into your pants!!!
QUOTE (swimmer+Dec 22 2005, 08:29 AM)
QUOTE (krreagan+Dec 22 2005, 05:16 AM)
Okay, I've lurked in the darkness for a while and have two answers for you.
1) Conditions are idealized. The belt reacts instantaneously. Therefore the car does not move because the car can never gain the upper hand, as it were! This is like having a belt that is mass-less, frictionless and rotates freely.
2) Conditions are realistic. The belt can only detect the speed of the car after the speed has actually changed, therefore the car will creep forward as long as the car can maintain an acceleration! Once the wheels stop accelerating, the car will stop moving forward! As long as the belt has to play catchup, the car will always be moving slightly faster then the belt so it will move forward!
My US$.02
Krreagan
Very good. That makes sense.
You stupid *** morons.....the question says it all, ONE POINT OF REFRENCE!!! Kreep has spoken...it is stupid to use two points of refrence, and you'll probably want to wash that...
1) Conditions are idealized. The belt reacts instantaneously. Therefore the car does not move because the car can never gain the upper hand, as it were! This is like having a belt that is mass-less, frictionless and rotates freely.
2) Conditions are realistic. The belt can only detect the speed of the car after the speed has actually changed, therefore the car will creep forward as long as the car can maintain an acceleration! Once the wheels stop accelerating, the car will stop moving forward! As long as the belt has to play catchup, the car will always be moving slightly faster then the belt so it will move forward!
My US$.02
Krreagan
Very good. That makes sense.
You stupid *** morons.....the question says it all, ONE POINT OF REFRENCE!!! Kreep has spoken...it is stupid to use two points of refrence, and you'll probably want to wash that...
QUOTE (Guest+Dec 23 2005, 12:41 AM)
QUOTE (swimmer+Dec 22 2005, 08:29 AM)
QUOTE (krreagan+Dec 22 2005, 05:16 AM)
Okay, I've lurked in the darkness for a while and have two answers for you.
1) Conditions are idealized. The belt reacts instantaneously. Therefore the car does not move because the car can never gain the upper hand, as it were! This is like having a belt that is mass-less, frictionless and rotates freely.
2) Conditions are realistic. The belt can only detect the speed of the car after the speed has actually changed, therefore the car will creep forward as long as the car can maintain an acceleration! Once the wheels stop accelerating, the car will stop moving forward! As long as the belt has to play catchup, the car will always be moving slightly faster then the belt so it will move forward!
My US$.02
Krreagan
Very good. That makes sense.
You stupid *** morons.....the question says it all, ONE POINT OF REFRENCE!!! Kreep has spoken...it is stupid to use two points of refrence, and you'll probably want to wash that...
Any idea of the context here?
Nah - didnt think so.
What was it like taking part in the Cornell study - which percentile were you actually in?
Obviously you were never able to "recognize the limitations of your abilities".
1) Conditions are idealized. The belt reacts instantaneously. Therefore the car does not move because the car can never gain the upper hand, as it were! This is like having a belt that is mass-less, frictionless and rotates freely.
2) Conditions are realistic. The belt can only detect the speed of the car after the speed has actually changed, therefore the car will creep forward as long as the car can maintain an acceleration! Once the wheels stop accelerating, the car will stop moving forward! As long as the belt has to play catchup, the car will always be moving slightly faster then the belt so it will move forward!
My US$.02
Krreagan
Very good. That makes sense.
You stupid *** morons.....the question says it all, ONE POINT OF REFRENCE!!! Kreep has spoken...it is stupid to use two points of refrence, and you'll probably want to wash that...
Any idea of the context here?
Nah - didnt think so.
What was it like taking part in the Cornell study - which percentile were you actually in?
Obviously you were never able to "recognize the limitations of your abilities".
QUOTE (WHAT??+)
Journal of Personality and Social Psychology
Unskilled and Unaware of It: How Difficulties in Recognizing One's Own Incompetence Lead to Inflated Self-Assessments
Justin Kruger and David Dunning
Department of Psychology
Cornell University
Abstract
People tend to hold overly favorable views of their abilities in many social and intellectual domains. The authors suggest that this overestimation occurs, in part, because people who are unskilled in these domains suffer a dual burden: Not only do these people reach erroneous conclusions and make unfortunate choices, but their incompetence robs them of the metacognitive ability to realize it. Across 4 studies, the authors found that participants scoring in the bottom quartile on tests of humor, grammar, and logic grossly overestimated their test performance and ability. Although their test scores put them in the 12th percentile, they estimated themselves to be in the 62nd. Several analyses linked this miscalibration to deficits in metacognitive skill, or the capacity to distinguish accuracy from error. Paradoxically, improving the skills of participants, and thus increasing their metacognitive competence, helped them recognize the limitations of their abilities.
Unskilled and Unaware of It: How Difficulties in Recognizing One's Own Incompetence Lead to Inflated Self-Assessments
Justin Kruger and David Dunning
Department of Psychology
Cornell University
Abstract
People tend to hold overly favorable views of their abilities in many social and intellectual domains. The authors suggest that this overestimation occurs, in part, because people who are unskilled in these domains suffer a dual burden: Not only do these people reach erroneous conclusions and make unfortunate choices, but their incompetence robs them of the metacognitive ability to realize it. Across 4 studies, the authors found that participants scoring in the bottom quartile on tests of humor, grammar, and logic grossly overestimated their test performance and ability. Although their test scores put them in the 12th percentile, they estimated themselves to be in the 62nd. Several analyses linked this miscalibration to deficits in metacognitive skill, or the capacity to distinguish accuracy from error. Paradoxically, improving the skills of participants, and thus increasing their metacognitive competence, helped them recognize the limitations of their abilities.
QUOTE (WHAT??+Dec 23 2005, 01:01 AM)
QUOTE (Guest+Dec 23 2005, 12:41 AM)
QUOTE (swimmer+Dec 22 2005, 08:29 AM)
QUOTE (krreagan+Dec 22 2005, 05:16 AM)
Okay, I've lurked in the darkness for a while and have two answers for you.
1) Conditions are idealized. The belt reacts instantaneously. Therefore the car does not move because the car can never gain the upper hand, as it were! This is like having a belt that is mass-less, frictionless and rotates freely.
2) Conditions are realistic. The belt can only detect the speed of the car after the speed has actually changed, therefore the car will creep forward as long as the car can maintain an acceleration! Once the wheels stop accelerating, the car will stop moving forward! As long as the belt has to play catchup, the car will always be moving slightly faster then the belt so it will move forward!
My US$.02
Krreagan
Very good. That makes sense.
You stupid *** morons.....the question says it all, ONE POINT OF REFRENCE!!! Kreep has spoken...it is stupid to use two points of refrence, and you'll probably want to wash that...
Any idea of the context here?
Nah - didnt think so.
What was it like taking part in the Cornell study - which percentile were you actually in?
Obviously you were never able to "recognize the limitations of your abilities".
1) Conditions are idealized. The belt reacts instantaneously. Therefore the car does not move because the car can never gain the upper hand, as it were! This is like having a belt that is mass-less, frictionless and rotates freely.
2) Conditions are realistic. The belt can only detect the speed of the car after the speed has actually changed, therefore the car will creep forward as long as the car can maintain an acceleration! Once the wheels stop accelerating, the car will stop moving forward! As long as the belt has to play catchup, the car will always be moving slightly faster then the belt so it will move forward!
My US$.02
Krreagan
Very good. That makes sense.
You stupid *** morons.....the question says it all, ONE POINT OF REFRENCE!!! Kreep has spoken...it is stupid to use two points of refrence, and you'll probably want to wash that...
Any idea of the context here?
Nah - didnt think so.
What was it like taking part in the Cornell study - which percentile were you actually in?
Obviously you were never able to "recognize the limitations of your abilities".
QUOTE (WHAT??+)
Journal of Personality and Social Psychology
Unskilled and Unaware of It: How Difficulties in Recognizing One's Own Incompetence Lead to Inflated Self-Assessments
Justin Kruger and David Dunning
Department of Psychology
Cornell University
Abstract
People tend to hold overly favorable views of their abilities in many social and intellectual domains. The authors suggest that this overestimation occurs, in part, because people who are unskilled in these domains suffer a dual burden: Not only do these people reach erroneous conclusions and make unfortunate choices, but their incompetence robs them of the metacognitive ability to realize it. Across 4 studies, the authors found that participants scoring in the bottom quartile on tests of humor, grammar, and logic grossly overestimated their test performance and ability. Although their test scores put them in the 12th percentile, they estimated themselves to be in the 62nd. Several analyses linked this miscalibration to deficits in metacognitive skill, or the capacity to distinguish accuracy from error. Paradoxically, improving the skills of participants, and thus increasing their metacognitive competence, helped them recognize the limitations of their abilities.
Kreegan, swimmer, sooks, bloy, atl5p, fargo...are you listening?
Unskilled and Unaware of It: How Difficulties in Recognizing One's Own Incompetence Lead to Inflated Self-Assessments
Justin Kruger and David Dunning
Department of Psychology
Cornell University
Abstract
People tend to hold overly favorable views of their abilities in many social and intellectual domains. The authors suggest that this overestimation occurs, in part, because people who are unskilled in these domains suffer a dual burden: Not only do these people reach erroneous conclusions and make unfortunate choices, but their incompetence robs them of the metacognitive ability to realize it. Across 4 studies, the authors found that participants scoring in the bottom quartile on tests of humor, grammar, and logic grossly overestimated their test performance and ability. Although their test scores put them in the 12th percentile, they estimated themselves to be in the 62nd. Several analyses linked this miscalibration to deficits in metacognitive skill, or the capacity to distinguish accuracy from error. Paradoxically, improving the skills of participants, and thus increasing their metacognitive competence, helped them recognize the limitations of their abilities.
Kreegan, swimmer, sooks, bloy, atl5p, fargo...are you listening?
Somebody is going to get some coal for christmas. Jeez lighten up.
While I've not been an angel at least I can say I understand where both sides are coming from on this.
I think it will fly, and I can give you reasons why. Now if you believe me or not, oh well. I've tried.
Looking at the mechanics and physics of it it looks clear to me.
While I've not been an angel at least I can say I understand where both sides are coming from on this.
I think it will fly, and I can give you reasons why. Now if you believe me or not, oh well. I've tried.
Looking at the mechanics and physics of it it looks clear to me.
QUOTE (Guest+Dec 22 2005, 05:21 PM)
QUOTE (krreagan+Dec 22 2005, 08:24 PM)
QUOTE (Illiac+Dec 22 2005, 12:28 PM)
QUOTE (SkiSTX+Dec 22 2005, 04:01 PM)
re: the car.
There are obviously 2 trains of thought here. And it has to do with how the phrase "moves forward" is interpreted. You can either take it to mean in relation to the belt or in relation to the tower/ground/calm air.
1--
If the 'speed' of the two objects is measured by radar guns from the tower which have to match each other at all times, then the car will achieve wind flow over it's wings. And the speeds could be as follows...
car radar speed = 50
belt radar speed = 50
wheel speed/car speedometer = 100
air speed over wings = 50
2--
If the 'speed' of the two objects is measured based on their own speedometers which have to match each other at all times, then the car will have zero wind over it's wings. And the speeds could be as follows...
car speedometer speed = 50
belt speedometer speed = 50
wheel speed/car speedometer = 50
air speed over wings = 0
--
So neither side is right or wrong... just a different interpretation of the question which doesn't explicitly state what 'moves forward' really means.
However, in scenario 2, the speedometer of the car is measuring it's speed in relation to the belt, and the belt is measuring it's speed in relation to the dirt beneath it. Is this wrong? Not necessarily, but I think it would be more correct/scientific to measure both speeds in relation to the same object as per scenario 1.
So I will agree to disagree with the 'car no flyiers'.
BTW I don't mean to put words in anyones mouth... this is just the way I am interpreting the two sides of the argument.
SkiSTX,
I think that Atl5p, Fargo and I (plus a few unidentified Guests) long ago agreed that there were two possible interpretations.
1. Speed of the plane is measured as movement forward from a stationary observer. This interpretation totally discounts any effect from the belt because it already says that the plane is moving forward away from a stationary observer and hence all actions of the belt must be netted out for that to occur. If that is your definition, then of course the problem is trivial and the plane will fly.
2. Speed of the plane is measured relative to the belt, just like you see on a treadmill in a gym a millions of times per day. The plane moves forward relative to the belt in one direction and the belt moves in the opposite direction at the same speed and the plane is stationary with respect to an outside observer, thus no airspeed and it will not fly.
The problem here has been a total refusal of the "it will fly" folks to acknowledge the second interpretation which has been muddled by all sorts of "new physics" such as "free wheeling", to support their claim that even if you did interpret the problem as case #2, the plane still would fly because there's nothing the conveyor could do to stop the forward motion of the plane. Now it seems that while there be some acknowledgment that #2 is possible, they want to argue that #1 is a "more correct interpretation" or even more amazing, that you couldn't build a controller to work for case #2 so therefore #1 has to be the only possible interpretation...incredible!! Now I am reading a post that suggests that you might be able to get a close match of speeds but that the plane would inch forward every so slightly so therefore it would always have the advantage over the belt....give me a break!! Certainly, you could just put a light sensor at the side of the conveyor about an inch ahead of the plane's wheel and when the wheel triggers the light, speed up the conveyor until the sensor goes out and with some smoothing intellegence the whole thing could probably match speeds within +- a couple inches/sec....that's not close enough??
Remember that the it will fly folks have to own up to a long history of posts about "free wheeling" which has been used both to support their case for interpretation #1 and also to refute all possibility of interpretation #2. I think that a new thread should be started on that topic alone just to capture the madness in one place.
I also think it has been interesting to note the difference in civility between the "it will fly" posters versus the "no fly" posters...wonder why that is? Alt5p has born the brunt of this because he's obviously put a LOT more energy into this debate but has for the most part (OK, one bad night) been extremely patient and civil.
Certainly this has been an interesting problem and a demonstration that any "learning" by web board is probably a futile effort as I don't see anyone changing their original stance on the problem after nearly 200 pages of argument.
Looks like I'll have to do this again...
The second interpretation violates that original question!
"The plane moves in one direction, while the conveyer moves in the opposite direction."
This implies a single unified reference frame outside both the plane and belt (ie... The ground!) Interpreting it as measuring one in terms of the other is a non sequitur.
"This conveyer has a control system that tracks the plane speed and tunes the speed of the conveyer to be exactly the same (but in opposite direction)."
"but in opposite direction" implies that the belt is not instantaneous in its measurement and since a second reference frame is not given, then only one can be assumed, the ground reference frame is to be used to measure the speed of the plane. Not to mention that speed is defined as distance per unit time. If it is instantaneous time is zero and you have a divide by zero...and an infinite acceleration of the wheels. And they call our logic flawed!
The second interpretation violates that original question!
"The plane moves in one direction, while the conveyer moves in the opposite direction."
This implies a single unified reference frame outside both the plane and belt (ie... The ground!) Interpreting it as measuring one in terms of the other is a non sequitur.
"This conveyer has a control system that tracks the plane speed and tunes the speed of the conveyer to be exactly the same (but in opposite direction)."
"but in opposite direction" implies that the belt is not instantaneous in its measurement and since a second reference frame is not given, then only one can be assumed, the ground reference frame is to be used to measure the speed of the plane. Not to mention that speed is defined as distance per unit time. If it is instantaneous time is zero and you have a divide by zero...and an infinite acceleration of the wheels. And they call our logic flawed!
"new physics" such as "free wheeling"
New?? I think the wheel was invented at least ten thousand yeas ago! Not what I would call new! The term "free wheeling" refers to the fact that the brakes are not on! (Again, an extremely difficult concept to grasp) You can see that their interpretation is flawed!
The light sensor he mentions, tracks the planes position of the plane not speed... again violating the original conditions of the question.
He is also forgetting that for a very long time they interpreted the question as we did, and they were saying that the friction in the wheels coupled with the planes weight, would not allow the plane to move forward. ( pages in the 50's .. 90's )
Pounding our head against a wall... and beating a dead horse all come to mind!
It's been evident throughout that their knowledge of physics and physical concepts as well as critical thinking skills are all lacking! As a matter of fact, Atl5p has actually learned quite a bit. If you go back and read his early posts they were horrible! The later ones, although still flawed showed much improvement in terminology and understanding.
Krreagan
It's obvious that Atl5p learned a ton....
And it's also obvious that special k needs to choose his inturpretation.
See, he just said the car would move forward...
But just a couple of pages ago, he had this little gem:
http://forum.physorg.com/index.php?showtop...indpost&p=46905
But just a couple of pages ago, he had this little gem:
http://forum.physorg.com/index.php?showtop...indpost&p=46905
Okay, I've lurked in the darkness for a while and have two answers for you.
1) Conditions are idealized. The belt reacts instantaneously. Therefore the car does not move because the car can never gain the upper hand, as it were! This is like having a belt that is mass-less, frictionless and rotates freely.
2) Conditions are realistic. The belt can only detect the speed of the car after the speed has actually changed, therefore the car will creep forward as long as the car can maintain an acceleration! Once the wheels stop accelerating, the car will stop moving forward! As long as the belt has to play catchup, the car will always be moving slightly faster then the belt so it will move forward!
My US$.02
Krreagan
Somethings gotta give special K
The it is IMPOSSIBLE for the car to be held back by that conveyor...the question says it all, the object WILL MOVE!
I refuse to acknowledge a "Guest" Register or shut the hell up!
Krreagan
There are obviously 2 trains of thought here. And it has to do with how the phrase "moves forward" is interpreted. You can either take it to mean in relation to the belt or in relation to the tower/ground/calm air.
1--
If the 'speed' of the two objects is measured by radar guns from the tower which have to match each other at all times, then the car will achieve wind flow over it's wings. And the speeds could be as follows...
car radar speed = 50
belt radar speed = 50
wheel speed/car speedometer = 100
air speed over wings = 50
2--
If the 'speed' of the two objects is measured based on their own speedometers which have to match each other at all times, then the car will have zero wind over it's wings. And the speeds could be as follows...
car speedometer speed = 50
belt speedometer speed = 50
wheel speed/car speedometer = 50
air speed over wings = 0
--
So neither side is right or wrong... just a different interpretation of the question which doesn't explicitly state what 'moves forward' really means.
However, in scenario 2, the speedometer of the car is measuring it's speed in relation to the belt, and the belt is measuring it's speed in relation to the dirt beneath it. Is this wrong? Not necessarily, but I think it would be more correct/scientific to measure both speeds in relation to the same object as per scenario 1.
So I will agree to disagree with the 'car no flyiers'.
BTW I don't mean to put words in anyones mouth... this is just the way I am interpreting the two sides of the argument.
SkiSTX,
I think that Atl5p, Fargo and I (plus a few unidentified Guests) long ago agreed that there were two possible interpretations.
1. Speed of the plane is measured as movement forward from a stationary observer. This interpretation totally discounts any effect from the belt because it already says that the plane is moving forward away from a stationary observer and hence all actions of the belt must be netted out for that to occur. If that is your definition, then of course the problem is trivial and the plane will fly.
2. Speed of the plane is measured relative to the belt, just like you see on a treadmill in a gym a millions of times per day. The plane moves forward relative to the belt in one direction and the belt moves in the opposite direction at the same speed and the plane is stationary with respect to an outside observer, thus no airspeed and it will not fly.
The problem here has been a total refusal of the "it will fly" folks to acknowledge the second interpretation which has been muddled by all sorts of "new physics" such as "free wheeling", to support their claim that even if you did interpret the problem as case #2, the plane still would fly because there's nothing the conveyor could do to stop the forward motion of the plane. Now it seems that while there be some acknowledgment that #2 is possible, they want to argue that #1 is a "more correct interpretation" or even more amazing, that you couldn't build a controller to work for case #2 so therefore #1 has to be the only possible interpretation...incredible!! Now I am reading a post that suggests that you might be able to get a close match of speeds but that the plane would inch forward every so slightly so therefore it would always have the advantage over the belt....give me a break!! Certainly, you could just put a light sensor at the side of the conveyor about an inch ahead of the plane's wheel and when the wheel triggers the light, speed up the conveyor until the sensor goes out and with some smoothing intellegence the whole thing could probably match speeds within +- a couple inches/sec....that's not close enough??
Remember that the it will fly folks have to own up to a long history of posts about "free wheeling" which has been used both to support their case for interpretation #1 and also to refute all possibility of interpretation #2. I think that a new thread should be started on that topic alone just to capture the madness in one place.
I also think it has been interesting to note the difference in civility between the "it will fly" posters versus the "no fly" posters...wonder why that is? Alt5p has born the brunt of this because he's obviously put a LOT more energy into this debate but has for the most part (OK, one bad night) been extremely patient and civil.
Certainly this has been an interesting problem and a demonstration that any "learning" by web board is probably a futile effort as I don't see anyone changing their original stance on the problem after nearly 200 pages of argument.
Looks like I'll have to do this again...
QUOTE
A plane is standing on runway that can move (some sort of band conveyer). The plane moves in one direction, while the conveyer moves in the opposite direction. This conveyer has a control system that tracks the plane speed and tunes the speed of the conveyer to be exactly the same (but in opposite direction).
The question is:
Will the plane take off or not? Will it be able to run up and take off?
The question is:
Will the plane take off or not? Will it be able to run up and take off?
The second interpretation violates that original question!
"The plane moves in one direction, while the conveyer moves in the opposite direction."
This implies a single unified reference frame outside both the plane and belt (ie... The ground!) Interpreting it as measuring one in terms of the other is a non sequitur.
"This conveyer has a control system that tracks the plane speed and tunes the speed of the conveyer to be exactly the same (but in opposite direction)."
"but in opposite direction" implies that the belt is not instantaneous in its measurement and since a second reference frame is not given, then only one can be assumed, the ground reference frame is to be used to measure the speed of the plane. Not to mention that speed is defined as distance per unit time. If it is instantaneous time is zero and you have a divide by zero...and an infinite acceleration of the wheels. And they call our logic flawed!
QUOTE (->
| QUOTE |
| A plane is standing on runway that can move (some sort of band conveyer). The plane moves in one direction, while the conveyer moves in the opposite direction. This conveyer has a control system that tracks the plane speed and tunes the speed of the conveyer to be exactly the same (but in opposite direction). The question is: Will the plane take off or not? Will it be able to run up and take off? |
The second interpretation violates that original question!
"The plane moves in one direction, while the conveyer moves in the opposite direction."
This implies a single unified reference frame outside both the plane and belt (ie... The ground!) Interpreting it as measuring one in terms of the other is a non sequitur.
"This conveyer has a control system that tracks the plane speed and tunes the speed of the conveyer to be exactly the same (but in opposite direction)."
"but in opposite direction" implies that the belt is not instantaneous in its measurement and since a second reference frame is not given, then only one can be assumed, the ground reference frame is to be used to measure the speed of the plane. Not to mention that speed is defined as distance per unit time. If it is instantaneous time is zero and you have a divide by zero...and an infinite acceleration of the wheels. And they call our logic flawed!
"new physics" such as "free wheeling"
New?? I think the wheel was invented at least ten thousand yeas ago! Not what I would call new! The term "free wheeling" refers to the fact that the brakes are not on! (Again, an extremely difficult concept to grasp) You can see that their interpretation is flawed!
The light sensor he mentions, tracks the planes position of the plane not speed... again violating the original conditions of the question.
He is also forgetting that for a very long time they interpreted the question as we did, and they were saying that the friction in the wheels coupled with the planes weight, would not allow the plane to move forward.
( pages in the 50's .. 90's )Pounding our head against a wall... and beating a dead horse all come to mind!
It's been evident throughout that their knowledge of physics and physical concepts as well as critical thinking skills are all lacking! As a matter of fact, Atl5p has actually learned quite a bit. If you go back and read his early posts they were horrible! The later ones, although still flawed showed much improvement in terminology and understanding.
Krreagan
It's obvious that Atl5p learned a ton....
And it's also obvious that special k needs to choose his inturpretation.
See, he just said the car would move forward...
QUOTE
"The plane moves in one direction, while the conveyer moves in the opposite direction."
This implies a single unified reference frame outside both the plane and belt (ie... The ground!) Interpreting it as measuring one in terms of the other is a non sequitur.
This implies a single unified reference frame outside both the plane and belt (ie... The ground!) Interpreting it as measuring one in terms of the other is a non sequitur.
But just a couple of pages ago, he had this little gem:
http://forum.physorg.com/index.php?showtop...indpost&p=46905
QUOTE (->
| QUOTE |
| "The plane moves in one direction, while the conveyer moves in the opposite direction." This implies a single unified reference frame outside both the plane and belt (ie... The ground!) Interpreting it as measuring one in terms of the other is a non sequitur. |
But just a couple of pages ago, he had this little gem:
http://forum.physorg.com/index.php?showtop...indpost&p=46905
Okay, I've lurked in the darkness for a while and have two answers for you.
1) Conditions are idealized. The belt reacts instantaneously. Therefore the car does not move because the car can never gain the upper hand, as it were! This is like having a belt that is mass-less, frictionless and rotates freely.
2) Conditions are realistic. The belt can only detect the speed of the car after the speed has actually changed, therefore the car will creep forward as long as the car can maintain an acceleration! Once the wheels stop accelerating, the car will stop moving forward! As long as the belt has to play catchup, the car will always be moving slightly faster then the belt so it will move forward!
My US$.02
Krreagan
Somethings gotta give special K
The it is IMPOSSIBLE for the car to be held back by that conveyor...the question says it all, the object WILL MOVE!
I refuse to acknowledge a "Guest" Register or shut the hell up!
Krreagan
I'm willing to stand here and defend ALL that I have said on this forum. If you are a "GUEST" I have no respect for your opinion! because you have no HONOR! It's easy to sit there are call others a liar or whatever and do it while remaining anonymous!
SHOW YOURSELF YOU COWARDS!
Krreagan
SHOW YOURSELF YOU COWARDS!
Krreagan
QUOTE (krreagan+Dec 23 2005, 02:55 AM)
I'm willing to stand here and defend ALL that I have said on this forum. If you are a "GUEST" I have no respect for your opinion! because you have no HONOR! It's easy to sit there are call others a liar or whatever and do it while remaining anonymous!
SHOW YOURSELF YOU COWARDS!
Krreagan
Didn't say you were a liar special K, just pointed out where you contradict yourself.
Damn, he get's awful defensive awful fast....
SHOW YOURSELF YOU COWARDS!
Krreagan
Didn't say you were a liar special K, just pointed out where you contradict yourself.
Damn, he get's awful defensive awful fast....
QUOTE (Guest+Dec 22 2005, 05:41 PM)
QUOTE (swimmer+Dec 22 2005, 08:29 AM)
QUOTE (krreagan+Dec 22 2005, 05:16 AM)
Okay, I've lurked in the darkness for a while and have two answers for you.
1) Conditions are idealized. The belt reacts instantaneously. Therefore the car does not move because the car can never gain the upper hand, as it were! This is like having a belt that is mass-less, frictionless and rotates freely.
2) Conditions are realistic. The belt can only detect the speed of the car after the speed has actually changed, therefore the car will creep forward as long as the car can maintain an acceleration! Once the wheels stop accelerating, the car will stop moving forward! As long as the belt has to play catchup, the car will always be moving slightly faster then the belt so it will move forward!
My US$.02
Krreagan
Very good. That makes sense.
You stupid *** morons.....the question says it all, ONE POINT OF REFRENCE!!! Kreep has spoken...it is stupid to use two points of refrence, and you'll probably want to wash that...
I suspect you are Atl5p as he has not shown his head here in a while!
You are a coward!
Krreagan
1) Conditions are idealized. The belt reacts instantaneously. Therefore the car does not move because the car can never gain the upper hand, as it were! This is like having a belt that is mass-less, frictionless and rotates freely.
2) Conditions are realistic. The belt can only detect the speed of the car after the speed has actually changed, therefore the car will creep forward as long as the car can maintain an acceleration! Once the wheels stop accelerating, the car will stop moving forward! As long as the belt has to play catchup, the car will always be moving slightly faster then the belt so it will move forward!
My US$.02
Krreagan
Very good. That makes sense.
You stupid *** morons.....the question says it all, ONE POINT OF REFRENCE!!! Kreep has spoken...it is stupid to use two points of refrence, and you'll probably want to wash that...
I suspect you are Atl5p as he has not shown his head here in a while!
You are a coward!
Krreagan
QUOTE (krreagan+Dec 23 2005, 02:55 AM)
I'm willing to stand here and defend ALL that I have said on this forum. If you are a "GUEST" I have no respect for your opinion! because you have no HONOR! It's easy to sit there are call others a liar or whatever and do it while remaining anonymous!
SHOW YOURSELF YOU COWARDS!
Krreagan
Okay, I've lurked in the darkness for a while and have two answers for you.
1) Conditions are idealized. The belt reacts instantaneously. Therefore the plane does not move because the car can never gain the upper hand, as it were! This is like having a belt that is mass-less, frictionless and rotates freely.
2) Conditions are realistic. The belt can only detect the speed of the car after the speed has actually changed, therefore the plane will creep forward as long as the car can maintain an acceleration! Once the wheels stop accelerating, the plane will stop moving forward! As long as the belt has to play catchup, the plane will always be moving slightly faster then the belt so it will move forward!
My US$.02
krusty fuckkedupinthehead contradictshimselfleftandright special so special k.
big guy has to vent online cause his wife wears the pants, won't let him have the remote, and his girls don't love him anymore cause they're getting pounded by the loosers in shop class, and all he has is his computer and online 'friends'...seen it before and it's not too pretty....
SHOW YOURSELF YOU COWARDS!
Krreagan
Okay, I've lurked in the darkness for a while and have two answers for you.
1) Conditions are idealized. The belt reacts instantaneously. Therefore the plane does not move because the car can never gain the upper hand, as it were! This is like having a belt that is mass-less, frictionless and rotates freely.
2) Conditions are realistic. The belt can only detect the speed of the car after the speed has actually changed, therefore the plane will creep forward as long as the car can maintain an acceleration! Once the wheels stop accelerating, the plane will stop moving forward! As long as the belt has to play catchup, the plane will always be moving slightly faster then the belt so it will move forward!
My US$.02
krusty fuckkedupinthehead contradictshimselfleftandright special so special k.
big guy has to vent online cause his wife wears the pants, won't let him have the remote, and his girls don't love him anymore cause they're getting pounded by the loosers in shop class, and all he has is his computer and online 'friends'...seen it before and it's not too pretty....
QUOTE (fuck-K+Dec 22 2005, 08:01 PM)
QUOTE (krreagan+Dec 23 2005, 02:55 AM)
I'm willing to stand here and defend ALL that I have said on this forum. If you are a "GUEST" I have no respect for your opinion! because you have no HONOR! It's easy to sit there are call others a liar or whatever and do it while remaining anonymous!
SHOW YOURSELF YOU COWARDS!
Krreagan
Didn't say you were a liar special K, just pointed out where you contradict yourself.
Damn, he get's awful defensive awful fast....
AN ignorant mind is a terrible thing!
Show me exactly where I contradicted myself and I will defend myself. Unlike some cowards that are so unsure of their themselves that they refuse to register.
Krreagan
SHOW YOURSELF YOU COWARDS!
Krreagan
Didn't say you were a liar special K, just pointed out where you contradict yourself.
Damn, he get's awful defensive awful fast....
AN ignorant mind is a terrible thing!
Show me exactly where I contradicted myself and I will defend myself. Unlike some cowards that are so unsure of their themselves that they refuse to register.
Krreagan
QUOTE (Guest+Dec 22 2005, 08:05 PM)
QUOTE (krreagan+Dec 23 2005, 02:55 AM)
I'm willing to stand here and defend ALL that I have said on this forum. If you are a "GUEST" I have no respect for your opinion! because you have no HONOR! It's easy to sit there are call others a liar or whatever and do it while remaining anonymous!
SHOW YOURSELF YOU COWARDS!
Krreagan
Okay, I've lurked in the darkness for a while and have two answers for you.
1) Conditions are idealized. The belt reacts instantaneously. Therefore the plane does not move because the car can never gain the upper hand, as it were! This is like having a belt that is mass-less, frictionless and rotates freely.
2) Conditions are realistic. The belt can only detect the speed of the car after the speed has actually changed, therefore the plane will creep forward as long as the car can maintain an acceleration! Once the wheels stop accelerating, the plane will stop moving forward! As long as the belt has to play catchup, the plane will always be moving slightly faster then the belt so it will move forward!
My US$.02
krusty fuckkedupinthehead contradictshimselfleftandright special so special k.
big guy has to vent online cause his wife wears the pants, won't let him have the remote, and his girls don't love him anymore cause they're getting pounded by the loosers in shop class, and all he has is his computer and online 'friends'...seen it before and it's not too pretty....
Sound like some 12 year olds cannot control themselves
Armature!
Krreagan
AN ignorant mind is a terrible thing!
Show me exactly where I contradicted myself and I will defend myself. Unlike some cowards that are so unsure of their themselves that they refuse to register.
Krreagan
THE CAR MOVES FORWARD YOU NUBM COKC SUCKING FAGGET
Register!
Krreagan
I'll register if you anser me this....what force causes the car to stay put?? There IS no force, because the question SAYS the car/plane whatever MUST MOVE FORWARD!!!
fukc-k
Register!
Krreagan
This faggot will side with a guest all day long, but now he wont answer one when he know's he's caught.....all it took was the right slip and a little time...
The question says the car moves forward, so it MUST move forward...everything this guys' been telling you fools is bullshit, and you follow the prickless speck like he's not the biggest bag of *** to ever post on this board.
He said the plane MOVES in one direction, and went to great lengths to explain why a fixed point should be used to measure the speed...
now he says the treadmill will hold the plane back if it matches speeds. Several of you were on the fence until your god led the way, for his sheeppeople.
So the car dosn't move because it can't get past the treadbelt holding it back via the wheels.
But the plane can move forward because the question SAYS it MOVES FORWARD.
what a looser full of shiite.
There are 3 questions that I have answered consistently (actually all but these are relevant).
1) The plane on a treadmill (Original question)
2) Car on idealized treadmill.
3) Car on realistic treadmill
If you want me to address these questions or only one Just register and ask!
I have been consistent with my physics and logic!
Now, Pick a question, register and I will explain!
Krreagan
SHOW YOURSELF YOU COWARDS!
Krreagan
Okay, I've lurked in the darkness for a while and have two answers for you.
1) Conditions are idealized. The belt reacts instantaneously. Therefore the plane does not move because the car can never gain the upper hand, as it were! This is like having a belt that is mass-less, frictionless and rotates freely.
2) Conditions are realistic. The belt can only detect the speed of the car after the speed has actually changed, therefore the plane will creep forward as long as the car can maintain an acceleration! Once the wheels stop accelerating, the plane will stop moving forward! As long as the belt has to play catchup, the plane will always be moving slightly faster then the belt so it will move forward!
My US$.02
krusty fuckkedupinthehead contradictshimselfleftandright special so special k.
big guy has to vent online cause his wife wears the pants, won't let him have the remote, and his girls don't love him anymore cause they're getting pounded by the loosers in shop class, and all he has is his computer and online 'friends'...seen it before and it's not too pretty....
Sound like some 12 year olds cannot control themselves
Armature!
Krreagan
I thought not!
Krreagan
Krreagan
QUOTE (***-k-really-hard-in-the-asss=k+Dec 22 2005, 08:19 PM)
QUOTE (krreagan+Dec 23 2005, 03:13 AM)
QUOTE (***-k+Dec 22 2005, 08:12 PM)
QUOTE (krreagan+Dec 23 2005, 03:10 AM)
QUOTE (Guest+Dec 22 2005, 08:09 PM)
QUOTE (krreagan+Dec 23 2005, 03:06 AM)
AN ignorant mind is a terrible thing!
Show me exactly where I contradicted myself and I will defend myself. Unlike some cowards that are so unsure of their themselves that they refuse to register.
Krreagan
QUOTE
"The plane moves in one direction, while the conveyer moves in the opposite direction."
This implies a single unified reference frame outside both the plane and belt (ie... The ground!) Interpreting it as measuring one in terms of the other is a non sequitur.
But just a couple of pages ago, he had this little gem:
http://forum.physorg.com/index.php?showtop...indpost&p=46905
QUOTE
Okay, I've lurked in the darkness for a while and have two answers for you.
1) Conditions are idealized. The belt reacts instantaneously. Therefore the car does not move because the car can never gain the upper hand, as it were! This is like having a belt that is mass-less, frictionless and rotates freely.
2) Conditions are realistic. The belt can only detect the speed of the car after the speed has actually changed, therefore the car will creep forward as long as the car can maintain an acceleration! Once the wheels stop accelerating, the car will stop moving forward! As long as the belt has to play catchup, the car will always be moving slightly faster then the belt so it will move forward!
My US$.02
Krreagan
This implies a single unified reference frame outside both the plane and belt (ie... The ground!) Interpreting it as measuring one in terms of the other is a non sequitur.
But just a couple of pages ago, he had this little gem:
http://forum.physorg.com/index.php?showtop...indpost&p=46905
QUOTE
Okay, I've lurked in the darkness for a while and have two answers for you.
1) Conditions are idealized. The belt reacts instantaneously. Therefore the car does not move because the car can never gain the upper hand, as it were! This is like having a belt that is mass-less, frictionless and rotates freely.
2) Conditions are realistic. The belt can only detect the speed of the car after the speed has actually changed, therefore the car will creep forward as long as the car can maintain an acceleration! Once the wheels stop accelerating, the car will stop moving forward! As long as the belt has to play catchup, the car will always be moving slightly faster then the belt so it will move forward!
My US$.02
Krreagan
THE CAR MOVES FORWARD YOU NUBM COKC SUCKING FAGGET
Register!
Krreagan
I'll register if you anser me this....what force causes the car to stay put?? There IS no force, because the question SAYS the car/plane whatever MUST MOVE FORWARD!!!
fukc-k
Register!
Krreagan
This faggot will side with a guest all day long, but now he wont answer one when he know's he's caught.....all it took was the right slip and a little time...
The question says the car moves forward, so it MUST move forward...everything this guys' been telling you fools is bullshit, and you follow the prickless speck like he's not the biggest bag of *** to ever post on this board.
He said the plane MOVES in one direction, and went to great lengths to explain why a fixed point should be used to measure the speed...
now he says the treadmill will hold the plane back if it matches speeds. Several of you were on the fence until your god led the way, for his sheeppeople.
So the car dosn't move because it can't get past the treadbelt holding it back via the wheels.
But the plane can move forward because the question SAYS it MOVES FORWARD.
what a looser full of shiite.
There are 3 questions that I have answered consistently (actually all but these are relevant).
1) The plane on a treadmill (Original question)
2) Car on idealized treadmill.
3) Car on realistic treadmill
If you want me to address these questions or only one Just register and ask!
I have been consistent with my physics and logic!
Now, Pick a question, register and I will explain!
Krreagan
I really must have blown his view of the universe for him to get so miffed! Some people just cannot stand the thought of being wrong. That's why I guess he refuses to register!
Krreagan
Krreagan
QUOTE (krreagan+Dec 23 2005, 03:32 AM)
I really must have blown his view of the universe for him to get so miffed! Some people just cannot stand the thought of being wrong. That's why I guess he refuses to register!
Krreagan
Oh yeah, the plane moves forward by default, but the car get's held back because it has an automatic transmission so it really isn't directly attatched to the engine by ANY stretch...so yeah, you've really blow up the universe alright!
Krreagan
Oh yeah, the plane moves forward by default, but the car get's held back because it has an automatic transmission so it really isn't directly attatched to the engine by ANY stretch...so yeah, you've really blow up the universe alright!
QUOTE (Guest+Dec 22 2005, 08:29 PM)
QUOTE (krreagan+Dec 22 2005, 10:17 PM)
QUOTE (Illiac+Dec 22 2005, 03:07 PM)
No Fly when speed of plane is taken as relative to the conveyor. (My assumption)
Fly if speed of plane is taken as forward motion away from fixed observer. (Not my assumption and not a very interesting problem as speed of plane is the independent variable...what's to determine?)
It's more interesting then the wheels/belt spinning to infinity on first forward motion? That's all your interpretation gives us! A feedback loop that quickly goes out of control!
Krreagan
what a great insight from krack-k
I have explained in great detail, my logic on this topic!
If you dispute it! find it, register and I'll explain!
As I have said I will stand behind all that I have put on this forum!
That cannot be said for you! Except for the 12 year old mouth, We don't know what is yours and what is other "guest" posters!
Krreagan
Fly if speed of plane is taken as forward motion away from fixed observer. (Not my assumption and not a very interesting problem as speed of plane is the independent variable...what's to determine?)
It's more interesting then the wheels/belt spinning to infinity on first forward motion? That's all your interpretation gives us! A feedback loop that quickly goes out of control!
Krreagan
what a great insight from krack-k
I have explained in great detail, my logic on this topic!
If you dispute it! find it, register and I'll explain!
As I have said I will stand behind all that I have put on this forum!
That cannot be said for you! Except for the 12 year old mouth, We don't know what is yours and what is other "guest" posters!
Krreagan
QUOTE (Guest+Dec 23 2005, 03:29 AM)
QUOTE (krreagan+Dec 22 2005, 10:17 PM)
QUOTE (Illiac+Dec 22 2005, 03:07 PM)
No Fly when speed of plane is taken as relative to the conveyor. (My assumption)
Fly if speed of plane is taken as forward motion away from fixed observer. (Not my assumption and not a very interesting problem as speed of plane is the independent variable...what's to determine?)
It's more interesting then the wheels/belt spinning to infinity on first forward motion? That's all your interpretation gives us! A feedback loop that quickly goes out of control!
Krreagan
what a great insight from krack-k
Hi there Atl-goon. Mad cause mommy and daddy took your toy away?
Fly if speed of plane is taken as forward motion away from fixed observer. (Not my assumption and not a very interesting problem as speed of plane is the independent variable...what's to determine?)
It's more interesting then the wheels/belt spinning to infinity on first forward motion? That's all your interpretation gives us! A feedback loop that quickly goes out of control!
Krreagan
what a great insight from krack-k
Hi there Atl-goon. Mad cause mommy and daddy took your toy away?
QUOTE (krreagan+Dec 22 2005, 08:24 PM)
QUOTE (Illiac+Dec 22 2005, 12:28 PM)
QUOTE (SkiSTX+Dec 22 2005, 04:01 PM)
re: the car.
There are obviously 2 trains of thought here. And it has to do with how the phrase "moves forward" is interpreted. You can either take it to mean in relation to the belt or in relation to the tower/ground/calm air.
1--
If the 'speed' of the two objects is measured by radar guns from the tower which have to match each other at all times, then the car will achieve wind flow over it's wings. And the speeds could be as follows...
car radar speed = 50
belt radar speed = 50
wheel speed/car speedometer = 100
air speed over wings = 50
2--
If the 'speed' of the two objects is measured based on their own speedometers which have to match each other at all times, then the car will have zero wind over it's wings. And the speeds could be as follows...
car speedometer speed = 50
belt speedometer speed = 50
wheel speed/car speedometer = 50
air speed over wings = 0
--
So neither side is right or wrong... just a different interpretation of the question which doesn't explicitly state what 'moves forward' really means.
However, in scenario 2, the speedometer of the car is measuring it's speed in relation to the belt, and the belt is measuring it's speed in relation to the dirt beneath it. Is this wrong? Not necessarily, but I think it would be more correct/scientific to measure both speeds in relation to the same object as per scenario 1.
So I will agree to disagree with the 'car no flyiers'.
BTW I don't mean to put words in anyones mouth... this is just the way I am interpreting the two sides of the argument.
SkiSTX,
I think that Atl5p, Fargo and I (plus a few unidentified Guests) long ago agreed that there were two possible interpretations.
1. Speed of the plane is measured as movement forward from a stationary observer. This interpretation totally discounts any effect from the belt because it already says that the plane is moving forward away from a stationary observer and hence all actions of the belt must be netted out for that to occur. If that is your definition, then of course the problem is trivial and the plane will fly.
2. Speed of the plane is measured relative to the belt, just like you see on a treadmill in a gym a millions of times per day. The plane moves forward relative to the belt in one direction and the belt moves in the opposite direction at the same speed and the plane is stationary with respect to an outside observer, thus no airspeed and it will not fly.
The problem here has been a total refusal of the "it will fly" folks to acknowledge the second interpretation which has been muddled by all sorts of "new physics" such as "free wheeling", to support their claim that even if you did interpret the problem as case #2, the plane still would fly because there's nothing the conveyor could do to stop the forward motion of the plane. Now it seems that while there be some acknowledgment that #2 is possible, they want to argue that #1 is a "more correct interpretation" or even more amazing, that you couldn't build a controller to work for case #2 so therefore #1 has to be the only possible interpretation...incredible!! Now I am reading a post that suggests that you might be able to get a close match of speeds but that the plane would inch forward every so slightly so therefore it would always have the advantage over the belt....give me a break!! Certainly, you could just put a light sensor at the side of the conveyor about an inch ahead of the plane's wheel and when the wheel triggers the light, speed up the conveyor until the sensor goes out and with some smoothing intellegence the whole thing could probably match speeds within +- a couple inches/sec....that's not close enough??
Remember that the it will fly folks have to own up to a long history of posts about "free wheeling" which has been used both to support their case for interpretation #1 and also to refute all possibility of interpretation #2. I think that a new thread should be started on that topic alone just to capture the madness in one place.
I also think it has been interesting to note the difference in civility between the "it will fly" posters versus the "no fly" posters...wonder why that is? Alt5p has born the brunt of this because he's obviously put a LOT more energy into this debate but has for the most part (OK, one bad night) been extremely patient and civil.
Certainly this has been an interesting problem and a demonstration that any "learning" by web board is probably a futile effort as I don't see anyone changing their original stance on the problem after nearly 200 pages of argument.
Looks like I'll have to do this again...
The second interpretation violates that original question!
"The plane moves in one direction, while the conveyer moves in the opposite direction."
This implies a single unified reference frame outside both the plane and belt (ie... The ground!) Interpreting it as measuring one in terms of the other is a non sequitur.
"This conveyer has a control system that tracks the plane speed and tunes the speed of the conveyer to be exactly the same (but in opposite direction)."
"but in opposite direction" implies that the belt is not instantaneous in its measurement and since a second reference frame is not given, then only one can be assumed, the ground reference frame is to be used to measure the speed of the plane. Not to mention that speed is defined as distance per unit time. If it is instantaneous time is zero and you have a divide by zero...and an infinite acceleration of the wheels. And they call our logic flawed!
There are obviously 2 trains of thought here. And it has to do with how the phrase "moves forward" is interpreted. You can either take it to mean in relation to the belt or in relation to the tower/ground/calm air.
1--
If the 'speed' of the two objects is measured by radar guns from the tower which have to match each other at all times, then the car will achieve wind flow over it's wings. And the speeds could be as follows...
car radar speed = 50
belt radar speed = 50
wheel speed/car speedometer = 100
air speed over wings = 50
2--
If the 'speed' of the two objects is measured based on their own speedometers which have to match each other at all times, then the car will have zero wind over it's wings. And the speeds could be as follows...
car speedometer speed = 50
belt speedometer speed = 50
wheel speed/car speedometer = 50
air speed over wings = 0
--
So neither side is right or wrong... just a different interpretation of the question which doesn't explicitly state what 'moves forward' really means.
However, in scenario 2, the speedometer of the car is measuring it's speed in relation to the belt, and the belt is measuring it's speed in relation to the dirt beneath it. Is this wrong? Not necessarily, but I think it would be more correct/scientific to measure both speeds in relation to the same object as per scenario 1.
So I will agree to disagree with the 'car no flyiers'.
BTW I don't mean to put words in anyones mouth... this is just the way I am interpreting the two sides of the argument.
SkiSTX,
I think that Atl5p, Fargo and I (plus a few unidentified Guests) long ago agreed that there were two possible interpretations.
1. Speed of the plane is measured as movement forward from a stationary observer. This interpretation totally discounts any effect from the belt because it already says that the plane is moving forward away from a stationary observer and hence all actions of the belt must be netted out for that to occur. If that is your definition, then of course the problem is trivial and the plane will fly.
2. Speed of the plane is measured relative to the belt, just like you see on a treadmill in a gym a millions of times per day. The plane moves forward relative to the belt in one direction and the belt moves in the opposite direction at the same speed and the plane is stationary with respect to an outside observer, thus no airspeed and it will not fly.
The problem here has been a total refusal of the "it will fly" folks to acknowledge the second interpretation which has been muddled by all sorts of "new physics" such as "free wheeling", to support their claim that even if you did interpret the problem as case #2, the plane still would fly because there's nothing the conveyor could do to stop the forward motion of the plane. Now it seems that while there be some acknowledgment that #2 is possible, they want to argue that #1 is a "more correct interpretation" or even more amazing, that you couldn't build a controller to work for case #2 so therefore #1 has to be the only possible interpretation...incredible!! Now I am reading a post that suggests that you might be able to get a close match of speeds but that the plane would inch forward every so slightly so therefore it would always have the advantage over the belt....give me a break!! Certainly, you could just put a light sensor at the side of the conveyor about an inch ahead of the plane's wheel and when the wheel triggers the light, speed up the conveyor until the sensor goes out and with some smoothing intellegence the whole thing could probably match speeds within +- a couple inches/sec....that's not close enough??
Remember that the it will fly folks have to own up to a long history of posts about "free wheeling" which has been used both to support their case for interpretation #1 and also to refute all possibility of interpretation #2. I think that a new thread should be started on that topic alone just to capture the madness in one place.
I also think it has been interesting to note the difference in civility between the "it will fly" posters versus the "no fly" posters...wonder why that is? Alt5p has born the brunt of this because he's obviously put a LOT more energy into this debate but has for the most part (OK, one bad night) been extremely patient and civil.
Certainly this has been an interesting problem and a demonstration that any "learning" by web board is probably a futile effort as I don't see anyone changing their original stance on the problem after nearly 200 pages of argument.
Looks like I'll have to do this again...
QUOTE
A plane is standing on runway that can move (some sort of band conveyer). The plane moves in one direction, while the conveyer moves in the opposite direction. This conveyer has a control system that tracks the plane speed and tunes the speed of the conveyer to be exactly the same (but in opposite direction).
The question is:
Will the plane take off or not? Will it be able to run up and take off?
The question is:
Will the plane take off or not? Will it be able to run up and take off?
The second interpretation violates that original question!
"The plane moves in one direction, while the conveyer moves in the opposite direction."
This implies a single unified reference frame outside both the plane and belt (ie... The ground!) Interpreting it as measuring one in terms of the other is a non sequitur.
"This conveyer has a control system that tracks the plane speed and tunes the speed of the conveyer to be exactly the same (but in opposite direction)."
"but in opposite direction" implies that the belt is not instantaneous in its measurement and since a second reference frame is not given, then only one can be assumed, the ground reference frame is to be used to measure the speed of the plane. Not to mention that speed is defined as distance per unit time. If it is instantaneous time is zero and you have a divide by zero...and an infinite acceleration of the wheels. And they call our logic flawed!
QUOTE (->