Question

In one of those very dark nights, Nerdeinstein aimed his flashlight at a pond at Brewster's angle. Using a light meter, he measured that the reflected light intensity is 49 Cd.

a) What is in Cd the intensity reading on the meter when a single ideal polarizer is inserted between the pond and the meter with the axis of the polarization of the polarizer perpendicular to the horizontal (pond surface)?

b) What is in Cd the intensity reading on the meter when a second polarizer is placed between the first and the meter with their axis of polarization perpendicular to each other (the first polarizer is still perpendicular to the horizontal)?

Answer 1

a) What is in Cd the intensity reading on the meter when a single ideal polarizer is inserted between the pond and the meter with the axis of the polarization of the polarizer perpendicular to the horizontal (pond surface)?

? angle between incident ray and plorizer = zero

I = I_ocos²? = 49*1 = 49 Cd

b) What is in Cd the intensity reading on the meter when a second polarizer is placed between the first and the meter with their axis of polarization perpendicular to each other (the first polarizer is still perpendicular to the horizontal)?

? = 90 here

I = zero