Posted by Delli on .
Light that is polarized along the vertical direction is incident on a sheet of polarizing material. Only 94% of the intensity of the light passes through the sheet and strikes a second sheet of polarizing material. No light passes through the second sheet. What angle does the transmission axis of the second sheet make with the vertical?
If no light gets through the second material, it must be passing only light polarized in the horizontal direction (perpendicular to the "transmission axis") of the first sheet.
We can use Malus law to solve this problem, equaiton 24.7:
S=amount of light leaving
So = amount of light entering
We know that S/So = 94%, or 0.94
Now, to solve for Θ from Malus law
S/So =cos2 Θ
Θ=cos-1 sqrt (S/So)
Θ= cos-1 sqrt (0.94)
We subtract this from 90 due to respct to the vertical
so 90-14.18= 75.82 degrees
The solution is almost correct, except that for the final answer it would be 90 + 14.18 = 104.18 degrees because the first sheet is already rotated 14.18 degrees from the vertical.
My apologies: the range for Θ is between 0 and 90 degrees, so the original answer of 75.82 degrees is correct.