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!

Energy in electromagnetic waves

  1. Mar 26, 2007 #1
    1. The problem statement, all variables and given/known data

    Find the electric and magnetic field amplitudes in an electromagnetic wave that has an average energy density of 3.0 J/m3.

    2. Relevant equations

    u=1/2 eo E^2 + 1/(2uo) B^2
    u=eo E^2
    u=B^2 /uo

    3. The attempt at a solution

    I tried using these equations, but I wasn't getting the right answer. Do I have to change the units or am I just using the wrong equations?
  2. jcsd
  3. Mar 26, 2007 #2
    just kidding...I figured it out :)
  4. Apr 1, 2008 #3
    how do you do it?!
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook