oh, but is the method correct?
edit: if velocity A is negative the answer would be -0.0627c and its still the wrong answer so there seems to be a problem with my method
Two chunks of rock, each having a mass of 1.00 kg, collide in space. Just before the collision, an observer at rest in the reference frame of a nearby star determines that rock A is moving toward the star at 0.800 c and rock B is moving away from the star at 0.750 c .
If the rocks stick...