question_answer 39)

                  A Merry-go-round, made of a ring-like platform of radius R and mass M, is revolving with angular speed \[\omega \]. A person of mass M is standing on it. At one instant, the person jumps off the round, radially away from the centre of the round (as seen from the round). The speed of the round afterwards is                 (a) \[2\omega \]                                               (b) \[\omega \]                 (c) \[\frac{\omega }{2}\]                                               (d) O                

Answer:

                  (b) Angular velocity of a rotating body changes only when external torque acts on it.