What should we do if we want to accumulate a negative charge on the Van De Graaff generator's metallic sphere? Draw a picture of the system and show the movement of the
charges on the drawing.

stands for electromotive force and it is measured in volts. despite its name, it is not actually the force in the sense of being a "pushing" or "pulling" (not measured in newtons).an equation that relates emf,  ℰ,  to a battery's terminal voltage, v, current, i, and internal resistance, r, is    ℰ = v + irin this case, the emf can be interpreted as a voltage—a difference in electric potential.i would not say that it would be considered an energy. if emf can be defined as the energy/work per a unit charge from a battery or other electric source, then it is not strictly energy.

Two cars collide, lock bumpers and move together after the collision.this collision is known as perfectly inelastic collision.

I'm pretty sure the answer is c