1. PF Contest - Win "Conquering the Physics GRE" book! Click Here to Enter
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Muon Half Life

  1. Feb 24, 2010 #1
    Hi All,

    I'm trying to do a Relativity problem and I'm having trouble.

    There is a detector on a balloon at 2000 meters above the earth that in one hour has detected 650 muons that normally have a half life of 1.5 microseconds. They are traveling at .99c towards the earth. How many are detected at the earth in one hour.

    Now due to time dilation, I get 10.633 microseconds for the half life relative to ground observers. That seems pretty reasonable.

    Now I figure that all I need to know is how long it takes for them to travel 2000 meters and that seems to be a classical calculation. Time =2000 meters/.99c but my answer is way off.

    Am I approaching this correctly? I am wondering about calculating the time it takes the muons to reach the ground in a classical manner?

    The book answer is 420 but I get over 600.

    Thank you,
  2. jcsd
  3. Feb 24, 2010 #2


    User Avatar
    Science Advisor
    Homework Helper

    I don't see that you've done anything wrong so far. How did you finally get to 'over 600'?
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook