Halliday, Resnick & Walker — Potential Energy and Conservation of Energy: Problem 74

A skier weighing 600 N goes over a frictionless circular hill of radius \(R = 20 \text{ m}\) (Fig. 8.45). Assume that the effects of air resistance on the skier are negligible. As she comes up the hill, her speed is 8.0 m/s at point B, at angle \(\theta = 20^\circ\). (a) What is her speed at the hilltop (point A) if she coasts without using her poles? (b) What minimum speed can she have at B and still coast to the hilltop? (c) Do the answers to these two questions increase, decrease, or remain the same if the skier weighs 700 N instead of 600 N?