A playground merry-go-round with a radius of 1.8 m and a rotational inertia of 120 kg m2 is stationary. A child with a mass of 25 kg gets on and…

A playground merry-go-round with a radius of 1.8 m and a rotational inertia of 120 kg m2 is stationary. A child with a mass of 25 kg gets on and walks around the edge of the merry-go-round. How many revolutions around the merry-go-round must the child make in order for the merry-go-round to make one full revolution?