Question

The angular velocity of second's hand of a watch will be :-

• A. $30\pi \text{rad/sec}$
• B. $\frac{\pi }{30}\text{rad/sec}$
• C. $60\pi \text{rad/ sec}$
• D. $\frac{\pi }{60}\text{rad/sec}$

Answer 1

The correct option is B $\frac{\pi }{30}\text{rad/sec}$

We know that second's hand completes its revolution $\left(2\pi \right)$ in $60\text{sec.}$

$\therefore$ The angular velocity is $\omega =\frac{\theta }{t}=\frac{2\pi }{60}=\frac{\pi }{30}\text{rad/sec.}$

Hence, option (b) is the correct answer.