Question

The average angular velocity of the seconds hand of a watch if the seconds hand of the watch completes one revolution in 1 minute is :

• A. $\frac{\pi }{15}rad{s}^{-1}$
• B. $\frac{\pi }{30}rad{s}^{-1}$
• C. $\frac{\pi }{45}rad{s}^{-1}$
• D. $\frac{\pi }{7}rad{s}^{-1}$

Answer 1

The correct option is B $\frac{\pi }{30}rad{s}^{-1}$

The average angular velocity is

$\omega =\frac{2\pi }{T}$. . . . . . . . . . . . .(1)

In second hand watch,

$1rev=1min=60sec$

$T=60sec$

From equation (1)

$\omega =\frac{2\pi }{60}$

$\omega =\frac{\pi }{30}rad/sec$

The correct option is B.