# Distance the muon travels?

1. Mar 2, 2004

### spidey007

i have a question
i have to do this problem
i know somewhat how it sets up but what do u take from the initial condition? do u take the distance the muon travels?
can someone help me set this bad boy up

Suppose a muon produced as a result of a cosmic ray colliding with a nucleus in the upper atmosphere has a velocity v = 0.9500c. Suppose it travels at constant velocity and lives 1.52 µs as measured by an observer who moves with it (this is the time on the muon's internal clock). It can be shown that it lives for 4.87 µs as measured by an earth-bound observer. Use c=2.997E+8 m/s and give all answers correct to 4 significant figures.
(a) How long would the muon have lived as observed on earth if its velocity was 0.0900c?
(b) How far would it have traveled as observed on earth?
(c) What distance is this in the muon's frame?

2. Mar 4, 2004

### Staff: Mentor

Re: help

This is a basic relativity problem; it probably should be moved to the Homework Help forum. (It sure doesn't belong in the Quantum Physics forum.)

Here are some tips:

Consider relativistic time dilation; you have the proper time.
Distance = speed x time.
Consider relativistic length contraction. (Or just use "Distance = speed x time" again.)