Could Someone Tell Me How to Work This (Physics) Problem?

Question

A skier has a horizontal velocity of 104.5 km/h at the end of a ramp, before a horizontal surface (the velocity is where the ramp and ground meet). The snow on both the horizontal surface and the ramp produces a coefficient of friction of .12 with the skis. If the initial velocity with which the skier started is twice the velocity of the final velocity (at the end of the horizontal surface), what distance will the skier travel overall?

I think that I need to divide out the ramp and horizontal surface into two parts, but I don't know what to do after that. Do I use Net Work is equal to change in Kinetic Energy or do I use Work of Friction is equal to Change in Kinetic Energy + Change in Potential Energy?

I would appreciate it if someone showed me how to do this type of problem!

I might not have been clear. The skier starts off at the top of the ramp. At the bottom of the ramp, he has the velocity of 104.5 km/h. He will continue with this velocity for some distance in the horizontal direction.

The distance I need to find is how far the skier travels from the beginning of the ramp to how ever far he travels across the horizontal surface.

Answer 1

Well, the ramp is actually irrelevant since we're concerned with the flat section here. So just imagine a flat surface with the skier entering at 104.5 km/h.

I'm assuming we're ignoring air drag and other sources of friction; so, since the platform is level, the only net force acting on the skier is the friction force. That is responsible for reducing the skier's speed.

So all you have to do is figure out the magnitude of the force, and based on that, figure out the time required to cut the speed in half, and from that you can determine the distance traveled.

You will need to know the mass of the skier.

Answer 2

http://en.wikipedia.org/wiki/Coefficient_of_friction