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Homework Help: Critical Angle Prism

  1. Sep 25, 2008 #1
    1. The problem statement, all variables and given/known data
    A corner reflector is to be made from a triangular prism with index of refraction n = 1.90, as shown in the diagram below. What is the maximum angle, with respect to the normal to the front surface of the prism, (theta), such that total reflection will occur?
    http://capa.sci.geneseo.edu/teacher/capalibrary/Graphics/Gtype73/prob02.gif (link to image)

    2. Relevant equations
    sin(critical angle)=(n1/n2)

    3. The attempt at a solution
    Tried using that equation, failed miserably.
  2. jcsd
  3. Sep 26, 2008 #2


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    Science Advisor
    Homework Helper

    Hi Aeighme! :smile:
    No … that's the equation for the maximum angle from glass (or whatever) into air.

    You need the ordinary sinθ1/sinθ2 = n2/n1 :smile:
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