Arifle of mass m is initially at rest, but is free to recoil. it fires a bullet of mass m with a velocity +v relative to the ground. part a after the rifle is fired, its velocity relative to the ground is after the rifle is fired, its velocity relative to the ground is −m/m√v. −mv/(m+m). −mv/m. −v.

Wish i knew this to !

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.