Answer Happy

* Incorrect The 154-lb ice skater with arms extended horizontally spins about a vertical axis with a rotational speed of 1.5 rev/sec. Estimate his rotational speed N if he fully retracts his arms, bringing his hands very close to the centerline of his body. As a reasonable approximation, model the extended arms as uniform slender rods, each of which is 28 in. long and weighs 12 lb. Model the torso as a solid 130-lb cylinder 13 in. in diameter. Treat the man with arms retracted as a solid 154-lb cylinder of 13-in. diameter. Neglect friction at the skate-ice interface. 1.5 rev/sec 13" -28" Answer: N = i rev/sec 4.16