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Homework Help: Destructive interference of light

  1. Apr 12, 2010 #1
    White light is shined perpendicularly onto a film of unknown thickness, with index of
    refraction n = 1.5.

    A. How thick would the film have to be for each of the following colors of light to
    be absorbed due to destructive interference? (15 points)

    Red (f = 4 * (10^14) Hz)
    Green (f = 5.45 * (10^14) Hz)
    Blue (f = 6.38 * (10^14) Hz)

    B. Draw a ray diagram that indicates the path of the red light from part A into and
    out of the film and justify the fact that red will not be seen in the reflected

    This online physics class blows me away at the homework questions it asks because it does not explain anything thoroughly. Wondering if someone could guide me in right direction, maybe which equation is best used here?
  2. jcsd
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