A bullet that has a mass of 120g is fired horizontally at a block of jelly of mass 10kg that is suspended from the ceiling by a uniform rod of mass 5 kg. Unfortunately, the designer of the experiment didn't pick a large enough block of jelly, and the bullet passed through the jelly and kept moving. After the bullet passed through the jelly, the experimenters measured the bullet to have a speed of 20m/s and the jelly block swung to a maximum height of 68cm higher than its initial height. How much energy was lost to heating up the jelly and the bullet?

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.