1. The problem statement, all variables and given/known data A spaceship moves away from a point at speed v and launches a smaller ship at speed v relative to the first ship. The second ship shoots a missile at speed v relative to the second ship 1. what is the speed of the second ship relative to Earth 2. what is the speed of the missile relative to Earth 2. Relevant equations 3. The attempt at a solution I assume that in order to get the speed of the first ship relative to Earth i just use the velocity transform u=(u'+v)/(1+[vu'/c^2]), which gives u= (v+v)/(1+[v^v/c^2]) or u= 2v/(1+[v^2/c^2]) Is this correct? If so, to find the speed of the missile relative to earth would i again use the same equation using the 2v/(1+[v^2/c^2]) as u'? Would this give the answer to part 2? Im confused.