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Homework Help: Path of Light Through a Circular Raindrop

  1. Feb 25, 2010 #1
    Path of Light Through a Circular (Spherical) Raindrop

    1. The problem statement, all variables and given/known data

    I need to draw an accurate diagram of a light ray's path through a circular raindrop.
    -The angle of incidence is 25degrees.
    -The radius is 4.15cm
    -n of water is ~1.33
    -n of air is ~1.000293

    I can calculate the first angle of refraction, but I cannot calculate the angle at which the light ray reflects from the raindrop. It does not say how in my textbook :frown:. Where is the normal?

    2. Relevant equations

    Snell's Law

    3. The attempt at a solution


    angle of refraction:

    Last edited: Feb 25, 2010
  2. jcsd
  3. Feb 25, 2010 #2
    Can somebody please help?:frown:
  4. Feb 25, 2010 #3
    Is this right or completely wrong?
    (except with the arrows pointing the correct way)
  5. Feb 25, 2010 #4


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    Homework Helper

    This is a sphere, so the normal at any point is the line that passes through the point, through the center, and straight to the other side.
  6. Feb 25, 2010 #5
    I'm going to guess this is the correct answer:

    Attached Files:

  7. Feb 26, 2010 #6


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    Staff Emeritus
    Science Advisor
    Homework Helper

    Looks right to me. Do they want you to calculate any of the distances in the figure, or is just getting the angles good enough?
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