Introduction to Classical Mechanics · Problem 11.40
Relativity (Kinematics) — Morin
Physics — Mechanics · people-clapping
Problem
Two people stand a distance L apart along an east--west road. They both clap their hands at precisely noon in the ground frame. You are driving eastward down this road at speed 4c/5. You notice that you are next to the western person at the same instant (as measured in your frame) that the eastern person claps. Later on, you notice that you are next to a tree at the same instant (as measured in your frame) that the western person claps. Where is the tree along the road? (Describe its location in the ground frame.)