Problem 1.361

Two relativistic particles move at right angles to each other in a laboratory frame of reference, one with the velocity \(v_{1}\) and the other with the velocity \(v_{2}\). Find their relative velocity.

v=\sqrt{v_{1}^{2}+v_{2}^{2}-\left(v_{1} v_{2} / c^{2}\right)}

Relativistic Mechanics