1. The problem statement, all variables and given/known data see attached. 2. Relevant equations centripedal acceleration: a=v^2/r 3. The attempt at a solution Okay I found the solution for part 1. http://www.vic.com/~syost/baylor/phy1422s07/final-answers2.pdf [Broken] question 2. I know the change in energy part. But I don't really understand how "Newton’s law states that the centripetal force must be the net radial force on the skater, which is the normal force FN directed radially outward, and the radial component of his weight, mg cos θ directed inward." and the equation that follows. I think I can do part 2 and 3 by vectors and projectile motion once the 1st part is solved.