what is the new angular speed & Change in KE?

Question

A merry-go-round rotates at the rate of 0.15 rev/s with an 85-kg man standing at a point 2.0 m from the axis of rotation.
(a) What is the new angular speed when the man walks to a point 0.7 m from the center? Assume that the merry-go-round is a solid 25-kg cylinder of radius 2.0 m.
in rad/sec
(b) Calculate the change in kinetic energy due to this movement.
in J

Answer 1

Find the inertia. Find the change in inertia. Use conservation of momentum to find the new speed. etc,.