## College Physics (4th Edition)

(a) The ball rolls through an angle of $6.0~rad$ (b) The ball's angular speed is $1.4~rad/s$
(a) We can find the angle $\theta$ through which the ball rolls: $\theta = \frac{d}{r} = \frac{15~cm}{2.5~cm} = 6.0~rad$ The ball rolls through an angle of $6.0~rad$ (b) We can find the ball's angular speed: $\omega = \frac{v}{r} = \frac{3.5~cm/s}{2.5~cm} = 1.4~rad/s$ The ball's angular speed is $1.4~rad/s$