Two identical twins, Sallie and Serena, are playing one December on a large merry-go-round (a disk mounted parallel to the ground on a vertical axle through its center) in their school playground in northern Minnesota. Each twin has a mass of 30.9 kg. The icy coating on the merry-go-round surface makes it frictionless. The merry-go-round revolves at a constant rate as the twins ride on it. Sallie, sitting a distance 1.85 m from the center of the merry-go-round, must hold on to one of the metal posts attached to the merry-go-round with a horizontal force of 59.0 N to keep from sliding off. Serena is sitting at the edge, a distance of 3.64 m m from the center; Serena must also hold on to a metal post on the merry-go-round to keep from sliding off.
Required:
What is the ratio of Serena?s speed to Sallie's speed (both speeds are measured by a stationary observer watching the spinnning merry-go-round)?