Given the lifetime of a muon as 2.197 microseconds, and the rest mass of 105.65MeV, and a total particle energy of 10GeV, I need to calculate how far, in the rest frame, the particle will travel before decay. 2. Relevant equations Beta=v/c Gamma=1/sqrt(1-beta^2) deltaT'=gamma*deltaT L'=L/gamma Attempts/Understanding Thus Far The equations aren't complicated but I can't quite make them mesh with my understanding. If deltaT' is the moving time, dividing it by gamma to get the stationary period will always yield a shorter time amount of time passing for the stationary period; isn't this the opposite of what I want? And, in order to figure out the total distance traveled, as measured in the rest frame, is it enough to multiply v*t'=L', then multiply by gamma to get the rest frame distance? Do I need to convert the time as well? Or would this lead to too many factors of gamma?