Path of Light Through a Circular Raindrop

AI Thread Summary
The discussion focuses on calculating the path of light through a circular raindrop, specifically addressing the angle of incidence at 25 degrees and the refractive indices of water and air. The user successfully calculates the first angle of refraction using Snell's Law, resulting in approximately 18.53 degrees. However, they express confusion regarding the angle of reflection and the concept of the normal line in relation to the spherical shape of the raindrop. Additional clarification is sought on whether further calculations, such as distances, are necessary beyond determining the angles. The conversation emphasizes the importance of understanding light behavior in spherical mediums.
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Path of Light Through a Circular (Spherical) Raindrop

Homework Statement



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?

Homework Equations



Snell's Law
nAsinA=nBsinB

The Attempt at a Solution



https://www.physicsforums.com/attachment.php?attachmentid=23940&d=1267138827g

angle of refraction:

B=sin-1((1.000293sin(25degrees))/1.33)=18.533
 
Last edited:
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Can somebody please help?:frown:
 
Is this right or completely wrong?
https://www.physicsforums.com/attachment.php?attachmentid=23944&d=1267153824
(except with the arrows pointing the correct way)
 
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.
 
Thanks!
I'm going to guess this is the correct answer:
 

Attachments

  • raindrop5.png
    raindrop5.png
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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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