A man standing on top of a train is hitting baseballs off the rear of the last compartment onto the embankment below. The roof of the train is 6.00m above the embankment. He hits the ball with initial velocity with respect to the train of -40 m/s in the horizontal direction. The train is moving 15 m/s with respect to the ground.
a) How long does it take to hit the ground?
b) How far does the ball travel horizontally (with respect to the ground) before it lands?
c) What is the VELOCITY of the ball with respect to the ground when it lands?
d) If the ball compresses the ground by one centimeter as it comes to rest when it hits the ground, what is the average force of the ground on the ball? Neglect gravity during this part of the motion, and just assume the ball enters the ground and moves in a straight line. HINT: It is easiest if you think of it in two parts. (1) How much work is done on the ball as it comes to a stop? (2) How does this amount of work depend on the force exerted by the ground and the ball, as it compresses the ground?
