Problem 21: Suppose you have three polarizing filters, with the second at an angle of 36° to the first and the third a

[answerhappygod]

Problem 21: Suppose you have
three polarizing filters, with the second at an angle of 36°
to the first and the third at an angle of 90° to the first.
What percent of the original intensity of unpolarized light
will the final intensity be after passing through all three
filters? I / I0 (%)
Problem 20: Suppose you have
polarized light of intensity 175 W/m2.
What will its intensity be after passing through a polarizing
filter with its axis at an 87° angle relative to the light’s
polarization direction? Give your answer in terms of
mW/m2.