A hockey puck slides across the ice at a constant speed. Which of the following is true?

1. It is in equilibrium.

2. The puck is at rest.

3. The puck is moving and thus not in equilibrium.

4. None of these

5. The puck can be considered neither at
rest nor in equilibrium.

The solar panels used by mark function because of the photoelectric effect. light shines on the cells causing electrons to be ejected from the metal, which produces an electric current. at night on mars, no light will fall on the solar cells and no electric current will be generated. according to your notes, what type of light is typically needed to cause the photoelectric effect? a)visible b)ultraviolet c)infrared