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hsphyss

10th November 2005 - 02:10 AM

Can anyone help me with this problem? Thank-you

A 0.025 kg golf ball moving at 23 m/s crashes through the window of a house in 1.0 10-4 s. After the crash, the ball continues in the same direction with a speed of 10 m/s. Assuming the force exerted on the ball by the window was constant, what was the magnitude of this force?

I tried (0.025)23-0.025(10)/1e-4 but it didnt work out

Drude

11th November 2005 - 01:37 AM

QUOTE

A 0.025 kg golf ball moving at 23 m/s crashes through the window of a house in 1.0 10-4 s. After the crash, the ball continues in the same direction with a speed of 10 m/s. Assuming the force exerted on the ball by the window was constant, what was the magnitude of this force?

momentum is inextricably assocaited with impulse and vice versa

Basically we know that

F = m a = m Δv / t so F . t = m Δv or in other words

F.t = impulse = m Δv = change of momentum

so having the formula F * t = m Δv

lets see what data your question gives to you:

m = .025 kg , v1=23 m/s , v2=10m/s so Δv = 10 - 23 = -13 m/s = 13 m/s (ignore the negative sign here since direction matters little in terms of the force since the force is always against the motion of the ball)

t = 1.0 10-4 s (I guess u meant 1.0E-4 or 1.0 * 10^-4 seconds?)

so we have m, t, Δv, and all we need is F

well,

F = m Δv / t = .025 * (13/ 1.0E-4) = 3250 N

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