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Waves and energy

  1. Oct 19, 2005 #1
    How do you find the total energy received by an EM wave in a period of time? I tried U=c * Area * time *power..but this doesnt seem to be right...any suggestions?
    Last edited: Oct 19, 2005
  2. jcsd
  3. Oct 19, 2005 #2


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    I'm not sure what you mean by an EM wave receiving energy but I assume you mean "flow of EM energy" or something to that effect. I hope I'm Poynting you in the right direction. :)
  4. Oct 20, 2005 #3

    Claude Bile

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    Tide is right, the Poynting vector will tell you the magnitude and direction of power flow along the wave.

    If you are not particularly fussed on the direction of power flow, then there is a simple scalar formulation as well;

    E = Intensity x Area x Time

    I'll leave it up to you to find out how to calculate the intensity.

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