1. The problem statement, all variables and given/known data Two spaceships A and B are launched from a point X, in opposite directions. At time t=15 minutes, spaceship A crashes. The velocity of the spaceships relative to X is 1.3x10⁸m/s. How far did the collision happen from B, as observed by astronauts on the spaceship? 2. Relevant equations x'=ɣ(x-vt) x=vt 3. The attempt at a solution I've calculated ɣ to be 1.11 The distance from spaceship A to the point X is 1.17x10¹¹m, so the distance from point B to x is also 1.17x10¹¹m. x'=ɣ(x-vt) x'=1.11(2*1.17x10¹¹-1.3x10⁸(60*15)) x'=1.30x10¹¹m So the distance is 2(1.17x10¹¹)+1.30x10¹¹=3.64x10¹¹m. I am probably using the equations incorrectly, so if anyone could help me out, it will be appreciated.