Question

Using expressions for power in rotational motion, derive the relation , where letters have their usual meaning.

Answer 1

We know that power in rotational motion, P = t ω

and K.E. of motion, E =1/2 I ω²  ......................(ii)

As power= time rate of doing work in rotational motion, and work is stored in the body in the form of K.E.

Using (i),P = t ω = I ω α or t = I α, which is the required relation.