Question

Page 13 9. A 49.8-kg athlete running at 4.54 m/s suddenly jumps onto a stationary playground merry-go-round at a distance 1.45 m from the axis of rotation of the merry-go-round. She is traveling tangential to the edge of the merry-go-round just before jumping on. The moment of inertia about its axis of rotation is 625 kg m2 and very little friction at its rotation axis. What is the angular speed of the merry-go-round just after she has jumped onto it? 10. A solid, uniform, horizontal disk with a diameter of 2.75 m and a mass of 5.29 kg freely rotates at 33? about a vertical axis through its center. A small 0.650-kg sticky object is suddenly dropped onto the disk and sticks to the disk at a distance of 94.5cm cm from the axis of rotation. The figure shows before and after views. (a) Before the object fell, what was the moment of inertia of the disk about its central axis? (b) After the object stuck, what was the moment of inertia of the system about the same axis? (c) What is the angular velocity of the disk (in rpm) after the stone fell onto the disk?