Variation of mass with velocity and its derivation

Do you know that there is variation of mass with velocity in relativity that is mass varies with the velocity when the velocity is comparable with the velocity of the light. Let us derive and discuss the variation of mass with the velocity relation:

Let there are two inertial frames of references S and S1. S is the stationary frame of reference and S’ is the moving frame of reference. At time t=t’=0 that is in the start, they are at the same position that is Observers O and O’ coincides. After that S’ frame starts moving with a uniform velocity v along x axis.

Suppose there are two particles moving in opposite direction in frame S’. velocity of particle A will be u’ and of B will be –u’ according to the observer O’. Continue reading “Variation of mass with velocity and its derivation”