A rigid and a disc of different masses are rotating with the same kinetic energy. If we apply a retarding torque `tau` on the ring, it stops after making n revolution. After how many revolutions will the disc stop, if the retarding torque on it is also `tau` ?

Options

A. `(n)/(2)`
B. `n`
C. `2n`
D. Data insufficient

Answer

B

Explanation

Work done by retarding torque = change in kinetic energy Since, kinetic energy of both are equal, both will rotate with same revolution.