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!

Relative length problem

  1. May 5, 2007 #1
    I'm attempting a question that reads: A moving meter stick is measured to be 80 cm. What is its speed?

    The related formula is L = Lo/gamma where gamma = 1 / (1 - (v/c)^2)^(1/2)

    I looked at the solution provided and the first statement is: Lo = 100cm. I understand the rest from there but I have no idea where this 100cm comes from. Can anyone explain?
  2. jcsd
  3. May 5, 2007 #2


    User Avatar
    Science Advisor

    They said it was a "meter stick", and 1 meter = 100 cm. This must be its length in its own rest frame.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook