The book states to stop particle B and calculate the velocity of A in B's frame.A spaceship 'A' leaves Earth with a velocity UA = 0.8c, and spaceship 'B' leaves in the same direction with velocity UB = 0.7c
What is the velocity of A relative to B?
i.e. transform velocity to a frame S' that means with velocity v(x) = UB = 0.7c
Transform UA to UA'
UA' = (UA - V) / [1 - (v/c^2)(UA)]
They then fill in values and obtain an answer of 0.23c. But I'm wondering where has this equation come from? I can see that it looks a bit like Lorrentz transformation gamma.
But if someone could explain exactly what's going on to obtain this equation? Has gamma been applied? Thank you