## Physics for Scientists and Engineers: A Strategic Approach with Modern Physics (4th Edition)

(a) At t = 1 s: $\omega = 6.3~rad/s$ (b) At t = 4 s: $\omega = 0$ (c) At t = 7 s: $\omega = -6.3~rad/s$
The angular velocity is the slope of the angular position versus time graph. (a) At t = 1 s: $\omega = \frac{\Delta \theta}{\Delta t}$ $\omega = \frac{4\pi~rad}{2~s}$ $\omega = 6.3~rad/s$ (b) At t = 4 s: $\omega = 0$ (c) At t = 7 s: $\omega = \frac{\Delta \theta}{\Delta t}$ $\omega = \frac{(-2\pi-4\pi)~rad}{3~s}$ $\omega = -6.3~rad/s$