A child of mass 40 kg stands beside a circular platform of mass 100 kg and radius 1.8 m spinning at 2.6 rad/s. Treat the platform as a disk. The child steps on the rim.
a) What is the new angular speed;
rad/s
b) She then walks to the center and stay there. What is the angular velocity of the platform then?
rad/s
c) What is the change in kinetic energy when she walks from the rim to the center of the platform?