# Conservation of Mechanical Energy-help

1. Dec 25, 2008

### moephysics

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

A skier starts from rest at the top of a hill. The skier coasts down the hill and up a second hill, as the drawing illustrates. The crest of the second hill is circular, with a radius of . Neglect friction and air resistance. What must be the height h of the first hill so that the skier just loses contact with the snow at the crest of the second hill?

I dont get the last part of this question I mean does the skier lose contact at the crest of the second hill or right before it or right after it. I just need some clarification with that and Ive attached the drawing that comes with the problem. Thats all and thank you

#### Attached Files:

• ###### ngr022.gif
File size:
4.1 KB
Views:
63
2. Dec 25, 2008

### Staff: Mentor

Assume that it means what it says: The skier loses contact at the crest of the hill (right at the top). What does that tell you about the forces on the skier at that point?

3. Dec 25, 2008

### moephysics

it tells me that he has gained enough kinetic energy so that he wont touch the crest at that point

4. Dec 25, 2008

### Staff: Mentor

OK, but how much is that? Hint: Consider the forces acting on the skier at that point.

5. Dec 25, 2008

### moephysics

well hes kind of undergoing circular motion so there must be a centripetal force acting on him if he were to go along the crest of the hill without losing contact with it.

Last edited: Dec 25, 2008
6. Dec 25, 2008

### moephysics

umm yea yea i get itt,, thanksss alot for you help :)