A playground merry-go-round has a radius of 4.20m and a moment of inertia of 255kg m2 and turns with negligible friction about a vertical axle through its center.
A) A child applies a 25.0N force tangentially to the edge of the merry-go-round for 18.0s . If the merry-go-round is initially at rest, what is its angular velocity after this 18.0s interval?
B) How much work did the child do on the merry-go-round?
C) What is the average power supplied by the child?