A train is moving along a track with constant speed v1 relative to the ground. A person on the train holds a ball of mass m and throws it toward the front of the train with a speed v2 relative to the train.

Part A

Calculate the change in kinetic energy of the ball in the Earth frame of reference.

Express your answer in terms of the variables m, v1, and v2.

Part B

Calculate the change in kinetic energy of the ball in the train frame of reference.

Express your answer in terms of the variables m, v1, and v2.

Part C

How much work was done on the ball in the Earth frame of reference?

Express your answer in terms of the variables m, v1, and v2.

Part D

How much work was done on the ball in the train frame of reference?

Express your answer in terms of the variables m, v1, and v2.