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Homework Help: Light wave

  1. Feb 9, 2006 #1
    The problem gives the angular frequency of a light wave (w) is represented by


    e^iw(t-nx/c)

    it says that sometimes n is replaced by the complex quantity n-ik.

    The question asks what is the effect of k on the wave. Also, it asks, what is its physical signifigance?


    I tried substituting in for n-ik for n, and then multiplying in the iw.


    I got: e^ (iwt-iwnx +kx)/c

    So I see that the k term is the only real term in the exponent, however I am not sure how that effects the wave, or what its physical signifigance is.
     
  2. jcsd
  3. Feb 9, 2006 #2

    quasar987

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    I don't think that is correct. Doing the calculations, I get, after putting into an illuminating form:

    [tex]e^{-kx/c}e^{i(wt-nx/c)}[/tex]

    What kind of a wave is that? (i.e. what is the effect of k on the wave?)
     
  4. Feb 9, 2006 #3
    thats a dampened wave, isn't it?
     
  5. Feb 9, 2006 #4
    and the larger the K, the quicker the wave dies?
     
  6. Feb 10, 2006 #5

    quasar987

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    yep.

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  7. Feb 10, 2006 #6
    sweet, thx dude.
     
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