Question

Question #aac4e

Answer 1

If a disk has changed its angular velocity from `omega` to `omega'` in `t s` due to angular deceleration of `alpha`,then

`omega'=omega - alpha*t`

Given, `omega'=0,omega =(2pi20),t=5` (as, `omega = 2pi nu = 2pi(1200/60)`)

So, `alpha = (40pi)/5=8pi=25.133 rads^-2`

So,angualar velocity of the block `2s` after the motion will be

`40pi - 8pi*2=40pi-16pi=75.4 rad s^-1`