[SOLVED] Not sure where to start.... 10. A playground merry-go-round is mounted on a frictionless axle, so it can only rotate in the horizontal plane. This object has a moment of inertia about the axle of I=50 kg m2, and it has a diameter of 2.2 meters. Initially it is turning at a constant rate so that it completes one revolution in 0.5 seconds. Standing next to it, you carefully place a block of mass m= 5.0 kg on the rotating table, so that it sits a distance r=1.0 m from the center. How long does it take to complete one rotation now? 1. 0.5 s 2. 0.55 s 3. 0.59 s 4. 0.63 s 5. 0.67 s 6. 0.71 s all i have is that i found wi = 12.57 rad/s...but i don't know what to do after that?