A man wishes to row the shortest possible distance from north to south across a river which is flowing at 2 km/hr from the east. He can row at 4 km/hr. (a) In which direction should he steer

From the diagram we have that

Therefore the direction is 30° from east of south

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.