Consider the merry-go-round of Practice Problem 8.1. The child is initially standing on the ground when the

Question:

Consider the merry-go-round of Practice Problem 8.1. The child is initially standing on the ground when the merry-go-round is rotating at 0.75 rev/s. The child then steps on the merry-go-round. How fast is the merry-ground rotating now? By how much did the rotational kinetic energy of the merry-go-round and child change?