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Homework Help: Basic physics question?

  1. Nov 28, 2011 #1
    Basic physics question???

    1. The problem statement, all variables and given/known data
    My younger sister has a problem stated:

    "An electromagnetic wave is found to have a frequency of 7.8x10-10 Hz. What is the speed of the wave?"

    2. Relevant equations

    3. The attempt at a solution

    It's been a while since I have done this, and I'm a little confused. I know that you typically use the formula: C=λv (C= speed of light, λ= wavelength, v=frequency). I'm not sure, but I was thinking maybe it's a trick question, because I thought electromagnetic waves all travel at the speed of light (~3x108 m/s). Am I correct in assuming this?

    Any help is appreciated.

  2. jcsd
  3. Nov 28, 2011 #2


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    Homework Helper

    Re: Basic physics question???

    Yes, I think you are right, it is a trick question, since the speed of light in vacuum is always ~3x108m/s
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