Chapter 10, Problem 62P

A tennis ball is a hollow sphere with a thin wall. It is set rolling without slipping at 4.03 m/s on a horizontal section of a track as shown in Figure P10.62. It rolls around the inside of a vertical circular loop of radius r = 45.0 cm. As the ball nears the bottom of the loop, the shape of the track deviates from a perfect circle so that the ball leaves the track at a point h = 20.0 cm below the horizontal section.

1. (a) Find the ball’s speed at the top of the loop.
2. (b) Demonstrate that the ball will not fall from the track at the top of the loop.
3. (c) Find the ball’s speed as it leaves the track at the bottom. What If?
4. (d) Suppose that static friction between ball and track were negligible so that the ball slid instead of rolling. Would its speed then be higher, lower, or the same at the top of the loop?
5. (e) Explain your answer to part (d).

Figure P10.62