This is a question off a take-home exam and I just need some help getting started on each part. 1. The problem statement, all variables and given/known data A train of length L moves at speed 3c/5 with respect to the ground. A ball is thrown from the back to the front, at speed c/3 with respect to the train. How much time does this take, and what distance does the ball cover in the train's frame, the ball's frame, and the ground's frame?