Question

The length of hour hand of a wrist watch is $1.5cm$. Find the magnitude of
(a) angular velocity
(b) linear velocity

Answer 1

Length of hour hand of a wrist watch is 1.5cm.
we know, angular velocity $\omega =\frac{2\pi }{t}$
here t is time taken to complete a circle.

$\omega =\frac{2\pi }{t}=\frac{\pi }{12\times 1800}$

and $v=r\omega$

so therefore

$v=\frac{2\pi r}{t}$

since it is given r = 1.5cm

so putting the values

$v=2.18\times {10}^{-6}$