Merry-Go-Round. Two identical twins, Jena and Jackie, 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 29.0 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. Jena, sitting a distance 1.71m 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 56.0 N to keep from sliding off. Jackie is sitting at the edge, a distance 3.58 m from the center. With what horizontal force must Jackie hold on to keep from falling off?