In a playground, there is a small merry-go-round of radius 1.20 m and mass 210 kg. its radius of gyration is 91.0 cm. (radius of gyration k is defined by the expression i=mk2.) a child of mass 44.0 kg runs at a speed of 4.50 m/s along a path that is tangent to the rim of the initially stationary merry-go-round and then jumps on. neglect friction between the bearings and the shaft of the merry-go-round. calculate?