PHYSICS
posted by Anna .
Hi! I have some questions from a study guide in my physics class, and they give me the answer, but I have to show how to get the answer. I did most of them, but need help with these. Here is problem #1:
A skier with a mass of 60.0 kg is standing at the top of a snow covered hill. As he slides down the hill, his height decreases by 42 m over a distance of 100 m of travel. How fast will he be going at the bottom of the hill (assuming no friction)? (28.7 m/s)

mgh=mv²/2
v=sqrt(2gh)=...