Hey there,
so a hockey ball is held 2 metres above the ground and has 3.2 joules of gravitational potential energy. It is then dropped...
how much kinetic energy does it have before it reaches the ground?
cheers thank you!
QUOTE (Yehia+Nov 1 2009, 04:04 PM)
Hey there,
so a hockey ball is held 2 metres above the ground and has 3.2 joules of gravitational potential energy. It is then dropped...
how much kinetic energy does it have before it reaches the ground?
cheers thank you!
Increasingly more than its potential energy when it was dropped.
Beyond that I cannot calculate an answer because I dropped my calculator from an equal height as the part of my brain that formulates and solves equations - I'm pretty sure they hit the ground and broke at the same moment though
so a hockey ball is held 2 metres above the ground and has 3.2 joules of gravitational potential energy. It is then dropped...
how much kinetic energy does it have before it reaches the ground?
cheers thank you!
Increasingly more than its potential energy when it was dropped.
Beyond that I cannot calculate an answer because I dropped my calculator from an equal height as the part of my brain that formulates and solves equations - I'm pretty sure they hit the ground and broke at the same moment though
The important thing about these types of problems is where you define your zero to be. If you're holding your ball of mass m at some height h then the GPE it has is mgh. The height is defined with respect to some zero point which is normally the ground (this isn't always the case though).
In your example, if the zero point is the ground and you've worked everything out correctly (I haven't checked) as the ball drops GPE is changed to kinetic energy. As it hits the ground all of the GPE has become KE so it will have 3.2 J of KE.
In your example, if the zero point is the ground and you've worked everything out correctly (I haven't checked) as the ball drops GPE is changed to kinetic energy. As it hits the ground all of the GPE has become KE so it will have 3.2 J of KE.
PhysOrg scientific forums are totally dedicated to science, physics, and technology. Besides topical forums such as nanotechnology, quantum physics, silicon and III-V technology, applied physics, materials, space and others, you can also join our news and publications discussions. We also provide an off-topic forum category. If you need specific help on a scientific problem or have a question related to physics or technology, visit the PhysOrg Forums. Here you’ll find experts from various fields online every day.
To quit out of "lo-fi" mode and return to the regular forums, please click here.