A skater has rotational interia 4.2 kg-m^2 with his fists held to his chest and 5.7 kg-m^2 with his arms outstretched. The skater is spinning at 3.0 rev/s while holding a 2.5 kg weight in each outstretched hand; the weights are 76 cm from his rotation axis. If he pulls his hands in to his chest, so they're essentially on his rotation axis, how fast will he be spinning? Find the work done by the skater puling the weights to his chest?