a playground merry-go-round (a disk) has a mass of 111 kg and a radius of 1.88 m and it is rotating with an angular velocity of 3.3 rad/s. what is its angular velocity (in si unit) after a 17 kg child gets onto it by grabbing its outer edge? the child is initially at rest. enter only the number of your answer in si units with 3 or more significant figures.