A skater spins with an angular speed of 12.0rad/s with his arms outstretched. He lowers his arms, decreasing his moment of inertia from 41kgm' to 36kgm2. a. Calculate his initial and final rotational kinetic energy. b. Does his rotational kinetic energy increase or decrease? c. What causes this change in kinetic energy?

A skater spins with an angular speed of 12.0rad/s with his arms outstretched. He lowers his arms, decreasing his moment of inertia from 41kgm' to 36kgm2. a. Calculate his initial and final rotational kinetic energy. b. Does his rotational kinetic energy increase or decrease? c. What causes this change in kinetic energy?