A train is moving along a track with constant speed relative to the ground. A person on the train holds a ball of mass and throws it toward the front of the train with a speed relative to the train.
a) Calculate the change in kinetic energy of the ball in the Earth frame of reference.
Express your answer in terms of the variables
b)Calculate the change in kinetic energy of the ball in the train frame of reference.
Express your answer in terms of the variables.