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Homework Help: (3 questions) Reflection and Refraction

  1. May 28, 2009 #1
    1. A light source, S, is located 2.0 m below the surface of a swimming
    pool and 1.5 m from one edged of the pool. The pool is filled to the
    top with water.
    a) At what angle does the light reaching the edge of the pool leave the
    b) Does this cause the light viewed from this angle to appear deeper or
    shallower than it actually is?

    2. ni*sinΘi = nr*sinΘr

    3. I have no idea how to do this problem.

    1. A ray of light is incident upon a 600-600-600 glass prism, n=1.5.
    the angle od incidence is 45 degree.
    a) Using Snell's law, determine the angle Θr to the nearest degree.
    b) Using elementary geometry, determine the values of angles A, B,
    and C.
    c) Determine angle of refraction.

    the picture is an attachment

    2. ni*sinΘi = nr*sinΘr

    3. a. ni*sinΘi = nr*sinΘr
    = sinΘr = nisinΘr/nr
    = 1sin60/1.5
    = 35.3 degrees

    b./c. I have no clue. I know its suppose to be simple geometry but I can't seem to figure it out. :/

    1. A sheet of plastic, n = 1.500, 25 mm thick is used in a bank teller's window. A ray of light strikes the sheet at an angle of 45 degrees. The ray leaves the sheet at 45 degrees but at a different location. Use a ray diagram to find the distance between the ray that leaves and the one that would have left in the plastic were not there.

    2. ni*sinΘi = nr*sinΘr

    3. How would you draw the ray diagram? I don't know if I need to use the 25 mm if so why and how?

    Thank YOU!! ;)

    Attached Files:

  2. jcsd
  3. May 28, 2009 #2


    User Avatar
    Homework Helper

    For 1 draw a picture and use your equation. It's just Snell's Law.

    You know the angle from the bottom, the index of refraction of water (look it up if you don't) ... just solve for the angle at exit.

    If you can't do that there's no point looking at the other questions.
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