Introduction to Classical Mechanics · Problem 11.57
Relativity (Kinematics) — Morin
Physics — Mechanics · relativity-simultaneity
Problem
Bullets on a train **
A train moves at speed v. Bullets are successively fired at speed u (relative to the train) from the back of the train to the front. A new bullet is fired at the instant (as measured in the train frame) the previous bullet hits the front. In the frame of the ground, what fraction of the way along the train is a given bullet, at the instant (as measured in the ground frame) the next bullet is fired? What is the maximum number of bullets that are in flight at a given instant, in the ground frame?