Old naval ships fired 11 kg cannon balls from a 220 kg cannon. it was very important to stop the recoil of the cannon, since otherwise the heavy cannon would go careening across the deck of the ship. in one design, a large spring with spring constant 2.5×104 n/m was placed behind the cannon. the other end of the spring braced against a post that was firmly anchored to the ship's frame.
what was the speed of the cannon ball if the spring compressed 55 cm when the cannon was fired?
express your answer using two significant figures.

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.