Problem - 20P37 A uniform disk-like merry-go-round of mass M and radius R is at rest when a child of mass m R and velocity v jumps on the platform. The diagram is a M view from above. The child lands a distance r from the axle, as shown, and then remains at rest relative to the platform. (Note that v is perpendicular to the initial radius vector r.) Find the subsequent an-gular speed of the merry-go-round, assuming negligible friction at the axle