1. The problem statement, all variables and given/known data A red light flashes at position xR = 3:00m and time tR = 1e-9s, and a blue light flashes at xB = 5:00m and tB = 9e-9 s, all measured in the S reference frame. Reference frame S` has its origin at the same point as S at t = t0 = 0; frame S' moves uniformly to the right. Both flashes are observed to occur at the same place in S'. (a) Find the relative speed between S and S`. (b) Find the location of the two flashes in frame S`. (c) At what time does the red flash occur in the S' frame? 2. Relevant equations 3. The attempt at a solution I am going crazy!!!!! This is my approach. taking the distance of S' from x_R to be L_p measured in S and distance of S' from x_B to be contracted length L_C as measured in S', [tex] L_p=L_c \times \gamma [/tex] [tex] x_A+2=x_A \times \gamma [/tex] at t_B distance travelled by S' frame is v X t' taking t' to be [tex]t_B \times gamma[/tex], [tex] x_A=3-vt' [/tex] But when i substituted [tex] x_A [/tex] back into the equation, i became stuck! so obviously something is wrong but i cannot figure out what is wrong.