A particle of mass M, which was initially at rest, is hit by a particle of mass m, which is travelling at the speed Vi. The two particles collide and travel in different directions at the same pace Vf. Find the mass ratio M/m in terms of ß = vi/c, assuming a relativistic, elastic collision. Demonstrate that this reduces to Vi 0, the nonrelativistic meaning.

A particle of mass M, which was initially at rest, is hit by a particle of mass m, which is travelling at the speed Vi. The two particles collide and travel in different directions at the same pace Vf. Find the mass ratio M/m in terms of ß = vi/c, assuming a relativistic, elastic collision. Demonstrate that this reduces to Vi 0, the nonrelativistic meaning.