How much energy is needed to perform 300 J of work?

Light traveling in a medium with a refractive index 1.19 is incident on a plate of another medium with index of refraction 1.79. at what angle of incidence is the reflected light fully polarized?

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

The diagram shows four locations in the electric field of a positive point charge m. at which location is the electric potential the greatest.