Dick and Jane’s coordinate axis both line up with the lab frame at time t=0 ---
ID: 2060277 • Letter: D
Question
Dick and Jane’s coordinate axis both line up with the lab frame at time t=0 --- the usual case.Jane is in a rocket ship that is travelling in the +y-direction with velocity v = c/2 (with respect to the lab) and throws a ball in the +x direction with velocity v = c/2 (in the frame of her rocket ship).
Similarly, Dick’s rocket ship is traveling in the +x-direction with velocity v = c/2 and he throws a baseball in the +y-direction with velocity v = c/2.
Find the velocity of Jane’s baseball in the frame of Dick’s baseball.
Explanation / Answer
The formula for relative velocity addition is
u = (v + u')/(1 + vu'/c2)
u = (.5c + .5c)/(1 + (.5c)(.5c)/c2)
u = .8c