What is the relative velocity of two observers with given object velocities?

[matheinste]

Hello dragan.

Just to make it clear to me, is the original question this :-

We are given a velocity (vector) in one frame and a velocity (vector) in another frame. The frames are moving relative to each other. We wish to know what is the velocity (vector) of the frames relative to each other.

Matheinste.

 

[dragan]

yes, precisely :) btw, we already have the solution, but the problem is interesting anyway. Most people usually say at first that it is a "standard" problem and it is enough to interchange the velocities (up to a minus sign) in the transformation formula.