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!

Angular Spread Of Blue and Red Light Through Plastic

  1. Oct 4, 2009 #1
    1. The problem statement, all variables and given/known data
    The index of refraction for blue light in plastic is 1.46 and for red light is 1.39. Determine the angular spread of the spectrum leaving the plastic block [presumably to air] for a beam of white light incident at angle of 45° to the plastic block.

    2. Relevant equations

    3. The attempt at a solution
    They are asking for white light, but I am only given blue and red?
    Using Snell's law to find:

    Blue - 1.46/1=sin45/sinX
    X= 28.97

    Red - 1.39/1=sin45/sinY

    Is that right? Would blue would leave at 28.97° and red at 31.33°. What about white light?

  2. jcsd
  3. Oct 4, 2009 #2


    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    What wavelength is white light?
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook