일반물리학 2 — Relativity: Problem 18

18 The mass of a muon is 207 times the electron mass; the average lifetime of muons at rest is \(2.20 \text{ \mu s}\). In a certain experiment, muons moving through a laboratory are measured to have an average lifetime of \(7.20 \text{ \mu s}\). For the moving muons, what are (a) \(\beta\), (b) \(K\), and (c) \(p\) (in \(\text{MeV/c}\))?