posted by Kevin .
A skater spinning with angular speed of 1.5 rad/s draws in her outstretched arms thereby reducing her moment of inertia by a factor a 3.
a) Find her final angular speed.
b)What is the ratio of her final angular momentum to her initial angular momentum?
c) Determine the ratio of her final kinetic energy to her initial kinetic energy.
d)Did her mechanical energy change? (Yes but why?)