Aball is falling toward the earth with a speed of 10m/s and has a mass of 0.5kg. what's the kinetic energy?

KE = ½ m x v2

KE = 0.5 ÷ 2 x 102 (10 x 10 = 100)

KE = 25

Kinetic energy equals half of the mass time the velocity squared therefor, half of 0.5 is 0.25 and 10 squared(or times itself again) is 100 multiply them together and you get 25

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.