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Homework Help: Total internal reflection diagram

  1. Mar 23, 2004 #1


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    ok, i need help with this one question. the diagram that goes with this question is at the following website: http://courseweb.edteched.uottawa.c...lems/PHY1102A-Assignment 4_files/image005.jpg

    i tried attaching it but it was too big. ok so here it is:
    A ray of light falls on a rectangular glass block (n = 1.5) that is almost completely submerged in water (n = 1.33) as shown in the figure above. (a) Find the angle theta for which total internal reflection just occurs at point P. (b) Would total internal reflection occur at point P for the value of theta found in (a) if the water were removed? Explain.

    for part a), i used the equation sin (theta) = n2/n1 and said that n2=1.33 and n1=1.5. this gave me a value for theta being 62degrees. is that it or is there more? thanks a lot.
    Last edited by a moderator: Apr 20, 2017
  2. jcsd
  3. Mar 24, 2004 #2
    There's more.

    1. You didn't finish part (a). You found the value for [tex]\theta_1[/tex], not [tex]\theta[/tex] (see drawing).

    2. You didn't give any answer to part (b).

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