7) A 10 kg cart is moving across a frictionless floor at 2.0 m/s. A 40 kg boy, riding in the cart, jumps off so that he hits the floor with zero velocity.
a. What impulse did the boy give to the cart?
b. What was the velocity of the cart after the boy jumped?

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.

Answermuch larger;