a 5.0-m radius playground merry-go-round with a moment of inertia of 2000 kg m2 is rotating freely with an angular speed of 1.0 rad/s. two people, each of mass 60 kg, are standing right outside the edge of the merry-go-round and suddenly step onto the edge with negligible speed relative to the ground. what is the angular speed of the merry-go-round right after the two people have stepped on?