Three perfectly polarizing sheets are spaced 2?cm {\rm cm} apart and in parallel planes. The transmission axis of the second she
et is 28 ? \deg relative to the first one. The transmission axis of the third sheet is 90 ? ^\circ relative to the first one. Unpolarized light impinges on the first polarizing sheet. What percent of this light is transmitted out through the third polarizer?
A polarizer is a complaint sheet for light in the polarization direction and blocks the perpendicular one. When we use two polarizers the transmission between them is described by Malus's law
I = I₀ cos² θ
Let's apply the previous exposures in our case, the light is indicatively not polarized, so the first polarized lets half of the light pass
I₁ = ½ I₀
The light transmitted by the second polarizer
I₂ = I₁ cos² θ
I₂ = (½ I₀) cos2 28
The transmission by the polarizing third is
I₃ = I₂ cos² θ₃
The angle of the third polarizer with respect to the second is
Oscillation whose amplitude reduce with time are called damped oscillation. This happen because of the friction. In oscillation if its amplitude doesn't change with time then they are called Undamped oscillation
