Question

A disc of radius 10 cm is rotating about its axis at an angular speed of 20 rad/s. Find the linear speed of
(a) a point on the rim,
(b) the middle point of a radius.

Answer 1

We know that $v=\omega r$

$\left(a\right)$ for a point on rim-

$v=20rad/s\times 10cm=200cm/s=2m/s$

$\left(b\right)$ for the middle point of radius- $r=5cm$

$v=20rad/s\times 5cm=100cm/s=1m/s$