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: Three polarizers are arranged as shown in the figure

  1. Nov 4, 2011 #1
    1. The problem statement, all variables and given/known data
    Three polarizers are arranged as shown in the figure. If the incident beam of light is unpolarized, and has an intensity of 1.60 W/m2, find the transmitted intensity for each of the following cases.

    25-29alt.gif

    (a) θ2 = 29.6° and θ3 = 44.0°
    (b) θ2 = 44.0° and θ3 = 29.6°

    2. Relevant equations
    I= 1/2I0
    I= I0cos2θ

    3. The attempt at a solution

    So what I did what for the first area i used
    I= 1/2I0 and I got .8
    then I2= .8cos2(29.6)= .6048
    then for I3= .6048cos2(44.0) =.2918

    then i did the same for part b only switched the theta as needed.

    Both of the answers are wrong. Ive been trying to think of why this could be wrong. I have tried many different ways, but this seems to be the one that makes most sense to me. If i could get any help that would be nice. Thanks in advance.
    1. The problem statement, all variables and given/known data



    2. Relevant equations



    3. The attempt at a solution
     
  2. jcsd
  3. Nov 5, 2011 #2

    Redbelly98

    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper

    Re: Polarization

    For that last step -- you need to use the angle between the 3rd polarizer's axis and the polarization of the light incident on that polarizer.
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook