Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

The proper mean lifetime of a sub-nuclear particle, called a muon, is 2 µs. Muon

ID: 2025425 • Letter: T

Question

The proper mean lifetime of a sub-nuclear particle, called a muon, is 2 µs. Muons in a beam are traveling at 0.982 c relative to a laboratory. The speed of light is 2.998 × 10^8 m/s.

In the reference frame of the muon, how far does the laboratory travel in a typical lifetime of 2 µs?
Answer in units of m.

What is this distance in the laboratory’s frame?
Answer in units of km.

I've tried to use the 1/sqrt(v^2/C^2) equation, but Can't get the right answer. Please show all the steps so I can do this on other problems.

Thanks!

Explanation / Answer

proper mean lifetime of a sub-nuclear particle, called a muon is ,t = 2 µs Muons in a beam are traveling at a speed , v = 0.982 c (relative to a laboratory) Here , c is the speed of the light = 2.998 × 108 m/s
(I) In the reference frame of the muon, how far does the laboratory travel in a typical lifetime of 2 µs is d = v t = (0.982c)(2s)                  = (0.982 x2.998 x 108 m/s)(2x10-6s)                  = 588.8 m (II) Acc.to special theory of relativity when the muon travels with a speed comparable to speed of the light , the profer meantime of the muon is when measured from laboratory frame is given by the formula t' = t / [1-v2/c2]         = (2 µs ) / [1-(0.982 c)2/c2]         =  10.58 µs thus, distance in the laboratory’s frame is        d' = v t'            = (0.982 x2.998 x 108 m/s)(10.58x10-6s)            = 3.114 Km (II) Acc.to special theory of relativity when the muon travels with a speed comparable to speed of the light , the profer meantime of the muon is when measured from laboratory frame is given by the formula t' = t / [1-v2/c2]         = (2 µs ) / [1-(0.982 c)2/c2]         =  10.58 µs thus, distance in the laboratory’s frame is        d' = v t'            = (0.982 x2.998 x 108 m/s)(10.58x10-6s)            = 3.114 Km