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Homework Help: Light - color of 250nm wave

  1. Nov 23, 2013 #1
    1. The problem statement, all variables and given/known data
    A 400 nm light ray is travelling through a vacuum.
    a.) Give the light’s speed, frequency and color.
    speed = 3E8: Correct
    frequency = 7.5E14: Correct
    color = violet: Correct

    b.) This light now passes into a material where n=1.6. Give the light’s speed, frequency, wavelength and color in this new medium.
    speed = 187.5E6 m/s: Correct
    frequency = 750E12 Hz: Correct
    wavelength = 250 nm: Correct
    color = no longer visible light: Your answer is incorrect.

    I thought visible light only goes from 400nm to 700nm--What am I missing?

    The other options are ROYBV
  2. jcsd
  3. Nov 23, 2013 #2

    rude man

    User Avatar
    Homework Helper
    Gold Member

    To your eye, what matters is frequency, not wavelength.
  4. Nov 23, 2013 #3
    Of course! Thank you!
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