The angular velocity of flywheel changes from `240` rpm to `120` rpm in `6` seconds. Calculate the no of revolutions it will make before coming to rest.

Explanation

`omega_(av)=(omega_(1)+omega_(2))/(2)=(240+120)/(2)xx(1)/(60) rev//s`
`=3 rev//s`
Number of revolution in `6` second
`theta=omega_(av)xxt`
`=3xx6` revolution
`=18` revolution
Use kinematics equations of rotational motion.