Coming to the bottom of a mountain, a skier moving with speed v collides with a
ID: 1349737 • Letter: C
Question
Coming to the bottom of a mountain, a skier moving with speed v collides with a barrier and is brought to a stop in an amount of time t. Over the course of the impact, the skier experienced an average net force F from the barrier. If the skier's initial velocity had been the same (v), but the time of impact to come to a full stop had been one-fourth as long (t / 4), what would have been the average net force exerted on the skier during the collision? The average net force would have been...a.) F b.) F/2 c.) 4F d.) F/4 e.) 2F
b.) if the time of the impact to come to a full stop had been the same(t) but the skiers velocity had been 4 times as much(4v) what would be the average net force exerted on the skier during the collision? The net force would have been.....a. 4F B.F/2 c.) 2F d.)F/4 e.) F
Explanation / Answer
F*t = m*v
Fnew*tnew = m*v
Fnew*(t/4) = m*v = F*t
Fnew = 4F
so the answer is C) 4F
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Fnew*t = m*4v
Fnew = m*v*4/t = F*t*4/t = 4F
so the answer is a) 4F