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Homework Help: Frequency Range Question

  1. Sep 22, 2009 #1
    Ultraviolet radiation is part of the electromagnetic spectrum that has wavelengths in the range of 200 nm to 400 nm. Given that the speed of all forms of electromagnetic radiation is 3.0 x 10^8 m/s, calculate the frequency range of ultraviolet radiation.

    Relevant equations:
    V = f(wavelength)

    vshallow/(wavelength) shallow = vdeep/(wavelength) deep

    The attempt at a solution:

    vshallow/(wavelength)shallow = vdeep/(wavelength)deep

    (3.0 x 10^8 m/s) / (4.0 x 10^-7m) = (3.0 x 10^8 m/s) / (2.0 x 10^-7m)

    (7.5 x 10^14 Hz) = (1.5 x 10^15 Hz)

    f = f2 - f1
    = (1.5 x 10^15 Hz) - (7.5 x 10^14 Hz)
    = 7.5 x 10^14 Hz

    I'm not sure if this is correct, but can someone please confirm? thanks
  2. jcsd
  3. Sep 22, 2009 #2


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    Hi wilson_chem90! :smile:

    (try using the X2 tag just above the Reply box :wink:)

    Yes, your calculations are fine :smile:

    (but I wonder whether by "range" they just want you to say "the range is from 7.5 x 1014 Hz to 1.5 x 1015 Hz" ?)
  4. Sep 22, 2009 #3
    thank you very much, i never thought of that. it makes more sense. I'll just put both answers just in case. Thank you!
  5. Sep 22, 2009 #4
    actually the way i answered would probably be the net frequency, so yours makes ALOT more sense.
  6. Sep 23, 2009 #5


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    :wink: goldfishsense! :biggrin:
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