A 75kg gunsmith uses a friction-less merry-go-round to estimate the speed of a .036g round fired from a gun. The merry-go-round has a rotational inertia of 85kgm2 and a 1.5m radius. He stands on the edge of the merry-go-round and fires the round in a tangential direction. She then measures the time it takes her to make one rotation and gets 65 seconds. What was the speed of the round?