A playground merry-go-round of radius r = 1.82m has a moment of inertia of i = 221kgm2 and is rotating at 14.8rev/min about a frictionless vertical axle. Facing the axle, a 22.4kg child hops onto the merry-go-round and manages to sit down on its edge. What is the work done by the child?
a) 567 J
b) 654 J
c) 723 J
d) 806 J