The mass of a muon is 207 times the electron mass; the average lifetime of muons at rest is 2.26 μs. In a certain experiment, muons moving through a laboratory are measured to have an average lifetime of 7.15 μs. For the moving muons, what are (a) β (b) K, and (c) p? The rest energy of the electron is 0.511 MeV. (a) Number Units (b) Number Units (c) Number Units