If a ray of light traveling in air strikes the surface of an amethyst crystal (n 1.553) at 35° toward the normal, what is the angle of incidence

Arescue plane flying horizontally at spots a survivor in the ocean directly below and releases an emergency kit with a parachute. because of the shape of the parachute, it experiences insignificant horizontal air resistance. if the kit descends with a constant vertical acceleration of, how far away from the survivor will it hit the waves?

Alfred pushes on a heavy box, but cannot move it. the box has a lot of inertia motion friction gravity

Which type of energy is transferred by convection currents?