Question: A man of mass m stands on a flat horizontal disc (mass M, radius R) near its edge. The disc is free to rotate without friction about its central axis. At a certain instant the man begins to walk around the disc with a constant velocity v with respect to the ground.
- If his feet do not slip on the disc, how long will it take him to return to the same point on the disc? Express your answer as a function of R, M, m and v
- Once he gets to the starting point, he stops walking. How long after he stops walking will it take the disc to stop turning?Explain
- The disc and the man are both stationary. If he walks in towards the centre of the disc, with a velocity u, how fast will the disc turn?Explain.
- The man again stands at the edge of the disc at rest. A ball of mass m/4 is thrown to him with velocity v tangent to the rim of the disc. He catches the ball. How fast does the disc turn? Express your answer as a function of R, M, m and v.