(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Some biologically active molecules rotate the direction of polarization of linearly polarized light, either clockwise or anticlockwise. For example, 5 gm of l-leucine dissolved in 100 mL of water causes a rotation by 0.550o while the same concentration of d-glutamic acid causes a rotation of 0.620o. If these solutions are placed between crossed polarizers illuminated by a beam of unpolarized light of intensity I=13 W/m2, what is the intensity of light transmitted by:

(a) the l-leucine solution? ___W/m^2

(b) the d-glutamic acid solution? ___W/m^2

2. Relevant equations

I=Io*cos^2(theta)

I=.5*Io

3. The attempt at a solution

To do this, for each solution, I plugged in the numbers in the equation:

for l-leucine: I=(13 W/m^2)(cos^2(0.62))

for d-glutamate: I=(13 W/m^2)(cos^2(0.55))

That didn't work. So I then tried finding I by doing:

I=(.5)(13)=6.75 then used this is the above equation and tried solving for Io then. That didn't work. A hint or suggestion would be greatly appreciated. Thank you!

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Intensity of Light by Polarizers

**Physics Forums | Science Articles, Homework Help, Discussion**