A 33.1-kg child runs with a speed of 2.80 m/s tangential to the rim of a stationary merry-go-round. The merry-go-round has a moment of inertia of 510 kg · m2 and a radius of 2.40 m. When the child jumps onto the merry-go-round, the entire system begins to rotate. Calculate both the initial and the final kinetic energy of the system.