Askater's body has rotational inertia 2.9kg·m2 by his fists held to his chest and 5.7 kg·m2 with arms outstretched. The skater is twirling at 3.0 rev/s while holding 2.3 kg weights in all outstretched hand; the weights are 76 cm from his rotation axis.
1) What is the rotational kinetic energy of the skater by weights in initial position?
2) What is the total angular momentum of the skater by weights?
3) If he pulls his hands in to his chest, how fast will he be twirling?