Two observers in the S frame, A and B, are separated by a distance of 60 m. Let S' move at a speed 0.6c relative to S (c is the speed of light), the origins of the two systems A' and A, being coincident at t'=t=3*10^-7 seconds, S' frame has two observers , one at A' and the other at B' such that according to clocks in the S frame, A' is opposite to A at the same time that B' is opposite to B.
The question is : What is the reading of the clock of B' when B' is opposite to B??
(Answer given in the book is 1.5*10^-7 seconds, but my answer turns out to be 2.25*10^-7 seconds. Kindly help)

Question

Two observers in the S frame, A and B, are separated by a distance of 60 m. Let S' move at a speed 0.6c relative to S (c is the speed of light), the origins of the two systems A' and A, being coincident at t'=t=3*10^-7 seconds, S' frame has two observers , one at A' and the other at B' such that according to clocks in the S frame, A' is opposite to A at the same time that B' is opposite to B.
The question is : What is the reading of the clock of B' when B' is opposite to B??
(Answer given in the book is 1.5*10^-7 seconds, but my answer turns out to be 2.25*10^-7 seconds. Kindly help)