A driver starts his parked car and within 4.6 seconds, reaches a velocity of 15 m/s. What is his acceleration?

Unpolarized light falls on two polarizer sheets whose transmission axes are at right angles. a third polarizer is placed between the first two so that its axis makes a 52-degree angle with the axis of the first polarizer. a) what fraction of the incident light intensity is transmitted through the first polaroid? b) what fraction of the incident light intensity is transmitted through the second polaroid? c) what is the angle of polarization of the light that enters the third polaroid? d) what fraction of the incident light intensity is transmitted through the third polaroid. e) what happens if the middle polaroid is removed?

Anybody wanna ? (picture included? )

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