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1. The problem statement, all variables and given/known data

A child riding a bicycle has a total mass of 40 kg. The child approaches the top of a hill that is 10 m high and 100 m long at 5 m/s. If the force of friction between the bicycle and the hill is 20 N, what is the child's velocity at the bottom of the hill?

2. Relevant equations

K = 1/2 * mv^2, U = mgh, W = delta E, W = Fx * cos(theta)

3. The attempt at a solution

Can someone check to see if I'm doing this correctly. I think what they're trying to say is that you're already at the top.

I would first do K-initial + U-initial = 4420 J. Then Then set that to Fx and solve for F which is 44.2 N. Subtract 20 N from that and you get 24.2 N and multiply it back by x which gives you 242 J. Set that to K-final and solve for v and you get 11 m/s.

Did I do everything correctly?

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# Homework Help: Please Check to See if I'm Doing Work-Energy Problem Correctly

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