Question

Two children, Angelica (mass 35 kg ) and Boris (mass 45 kg ), are playing on a merry-go-round (which you can assume is a solid disk with mass 250 kg  and radius 1.5m). Assume that any friction on the axle of the merry-go-round is negligible.

Part A

Angelica starts spinning the merry-go-round, giving it an angular velocity of 7 rad/s , then she stops pushing it. Boris runs with a speed of 7 m/s directly toward the center of the merry-go-round. He jumps and lands on the edge of the merry-go-round. What is the angular speed of the merry-go-round once Boris lands on it?

Part B

After landing, Boris walks to the center of the merry-go-round. What is the angular speed of the merry-go-round when he gets to the center?

Part C

While Boris is in the center of the merry-go-round, Angelica runs up with a speed of 6 m/s  tangentially in the same direction the merry-go-round is spinning, jumping onto the edge of the merry-go-round. What is the angular speed of the merry-go-round after Angelica lands on it?

Part D

Angelica stays in place while Boris walks back to the edge of the merry-go-round. What is the angular speed of the merry-go-round when he gets there?

Answer 1