Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Refraction of light in three mediums

  1. Mar 10, 2008 #1
    1. 2 cases:
    there are three mediums
    first case: light travels from first medium to second, then to third. n1 = 1.1; n2 =1.6; n3 =1.9
    angle of incidence before first = theta 1
    angle of refraction after first = theta 2
    angle of refraction after second = theta 3

    second case:
    light travels through three mediums
    n1' = n1
    n2' = 1.5
    n3' = n3
    theta 1' = theta 1

    2. R = sin theta 3' / sin theta 3
    what should be the value of R?

    3. I keep getting 1. I donno why though?
  2. jcsd
  3. Mar 10, 2008 #2
    Snell's Law for the general case says that n1sin(theta1) = n2sin(theta2) and since the angle into the second interface is the same as the angle out of the first interface, n2sin(theta2) = n3sin(theta3). So n1sin(theta1) = n3sin(theta3). So the index of refraction of the middle medium doesn't change the final angle out. That's the meaning of R=1, right?
  4. Mar 10, 2008 #3
    yes...i dont think its right though
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook