An atom of hydrogen consists of one surrounded by one

Unpolarized light of intensity so passes through two sheets of polarizing material whose transmission axes make an angle of 60∘ with each other as shown in the figure. what is the intensity of the transmitted beam, st?

An object weighs 40n in air, weighs 20n when submerged in water and 30n when submerged in a liquid of unknown density. what is the density of the liquid?

For the car in the picture ,in which direction is the normal force? -into the screen -down -out of the screen -up