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Homework Help: Intensity of red laser vs blue laser

  1. Sep 3, 2007 #1
    1. The problem statement, all variables and given/known data:
    Consider two lasers, one blue and one red. Which of the two lasers has the higher intensity?

    2. these are my choices:
    The blue one.
    Cannot be decided based on the information given.
    The red one.

    3. The attempt at a solution:
    The difference between these two lasers is their wavelength. Red has a higher wavelength than blue. Both have the same velocity, so red also has a lower frequency than blue (because v = wavelength * frequency). However, intensity depends on amplitude. (this is where I'm not sure) Amplitude does not depend on wavelength even though the displacement depends on both amplitude and wavelength, so we cannot decide with the given information.

    am i right or totally off?
  2. jcsd
  3. Sep 4, 2007 #2


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    You are completely right.
  4. Sep 5, 2007 #3
  5. Sep 5, 2007 #4
    I also think the intensity is given by the amplitude.. Just like volume in sound is given by it.
  6. Sep 24, 2011 #5
    Thanks for your website services.

    Blue Lasers
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