Amuon is traveling at 0.981 c. what is its momentum? (the mass of such a muon at rest in the laboratory is 207 times the electron mass.)

The rest mass of the muon is 207 times the mass of the electron:


The relativistic momentum of a particle is given by

where
m is the particle's mass
v is its velocity
is the relativistic factor, with c being the speed of light.

The muon is traveling at speed , so the relativistic factor is


So the momentum of the muon is