Question

A rotating wheel has a speed of $1200$ rpm and the it is made to slow down at a constant rate at $2rad/s^2$.The number of revolution it makes before coming to rest will be:

Answer 1

$v^2-u^2=2aS$ this applies n rotation to
$v\to w_{final}$ $u\to w_{initial}$
$1200\times \frac{2\pi }{60}=v=40\pi ,u=0$
$\theta =s=\frac{(40\pi {)}^2}{2a}=\frac{1600{\pi }^2}{2\times 2}=400{\pi }^2=\left(200\pi \right)\left(2\pi \right)$ no of rotation