#### Answer

(a) $\omega = 4.7~rad/s$
(b) The period is 1.3 seconds.

#### Work Step by Step

(a) $\omega = (45~rpm)(\frac{2\pi~rad}{1~rev})(\frac{1~min}{60~s})$
$\omega = 4.7~rad/s$
(b) $P = \frac{2\pi~rad}{4.7~rad/s}$
$P = 1.3~s$
The period is 1.3 seconds.