A woman with mass 50 kg stands at the rim of a large disk rotating at 0.5 rev/s about its center axis. The disk has
mass 100 kg and radius 4.0 m. The woman moves until she is 1.0 m from the center.
(i) What is the speed in rev/s after she has moved?
(ii) What is the difference in energy of the system? Where did this energy come from or go to?