What two things does light provide?

Unpolarized light of intensity i_0=750w/m^2 is incident upon two polarizers. after passing through both polarizers the intensity is i_2=280w/m^2. (a) what is the intensity of the light after it passes through the first polarizer in w/m^2? (b) write an equation for the angle between the polarizers in terms of the initial (i_0) and final (i_2) intensities. (c) find the angle between the polarizers in degrees.

What was the purpose of the apollo program? to put a man in orbit to launch a spy satellite to launch a space station to put man on the moon

How can you measure the amplitude of a longitudinal wave?