If a ball is rolling at a velocity of 1.5 m/sec and has a momentum of 10.0 kg·m/sec, what is the mass of the
ball?

Momentum = (mass) x (speed)

10 kg-m/sec = (mass) x (1.5 m/s)

Divide each side by  1.5 m/s :

Mass =  10 kg-m/sec / 1.5 m/s  =  (6 and 2/3) kg

Milliseconds. . . . . .

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.