Amerry-go-round is a common piece of playground equipment. a 3.0-m-diameter merry-go-round, which can be modeled as a disk with a mass of 290 kg , is spinning at 25 rpm. john runs tangent to the merry-go-round at 5.6 m/s, in the same direction that it is turning, and jumps onto the outer edge. john's mass is 30 kg.