Question

A wheel rotation at a speed of 600 rpm (revolutions per minute) about its axis is brought to rest by applying a constant torque for 10 seconds. Find the angular deceleration and the angular velocity 5 seconds after the application of the torque.

Answer 1

A wheel rotation at a speed of 600 rpm

${\omega }_0=600\text{rpm}$

=10 revolutions per second

r = 10 sec (in 10 sec it comes to rest)

$\omega =0$

Therefore ${\omega }_0$ = -at

$\Rightarrow a=-\frac{10}{10}=-1rev/s^2$

$\Rightarrow \omega ={\omega }_0+at$

= $10-1\times 5=5rev/s^2$

Therefore angular deceleration

$=1rev/s^2$ and

Angular velocity after 5 sec is 5 rev/s.