A playground merry-go-round has a mass of 120 kg and a radius of 1.80 m and it is rotating with an angular velocity of 0.500 rev/s. What is its angular velocity after a 22.0-kg child gets onto it by grabbing its outer edge? The child is initially at rest.

Step-by-step solution Step 1 of 3 The conservation of angular momentum can be applied, as no external torque is acted upon the merry-go-round. So, initial angular momentum is equal to final angular momentum of the system. Here, is the moment of inertia of the merry-go-round, is the angular velocity of the merry-go-round, is the moment of inertia of the system with the kid at the edge of the merry-go-round and is the required angular velocity.