1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
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: Light Refracted Through A Prism

  1. Nov 25, 2007 #1
    [SOLVED] Light Refracted Through A Prism

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

    Two parallel rays enter the longest side of a prism of refractive index 1.52. The prism is isosceles in shape and has angles of 23, 23 and 134 degrees. Assuming that the rays enter the prism on either side of the perpenical divider (ie at least half of the length of the prism side between them) what is the measure of the angle between the two emerging rays?

    2. Relevant equations


    3. The attempt at a solution

    My biggest problem is that i'm not sure how to deal with the unknown angle of incidence or refraction. If I take n(air) = 1, then the above equation would read sin(angle of incidence)/sin(angle of refraction)=1.52 which just gives me another wording of Snell's Law. I've tried dealing with only half of the prism so I have a right-angled triangle with angles 23 and 67, but in truth I'm really not sure how to even approach this. Any help at all would be great. Thanks!
  2. jcsd
  3. Nov 26, 2007 #2


    User Avatar
    Homework Helper

    Suppose two parallel rays enter the longest side of a prism of refractive index 1.52 perpendicular to the longest side. They enter the prism without deviation.The angle of incedence on the other face is equal to 23 degree. Find the angle of refraction and angle of deviation for one ray. Double the deviation is the angle between the refracted rays.
  4. Nov 26, 2007 #3
    This is where I had trouble... I wasn't sure I could assume that the rays were perpendicular to the prism, since the question doesn't specifically state this.
  5. Nov 26, 2007 #4
    Sorry, my mistake, must read question more carefully! Thank you!
  6. Feb 24, 2008 #5
    i didnt get it....
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook