Two students have volunteered to explore the galaxy in a spaceship .As they travel through space, they measure the magnitude of the gravitational force between their spaceship and the earth . They find that the gravitational force on the spaceship is

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.

Ibelieve the answer is either b or c, but i'm leaning more towards c.hope my answer has you : )

How are period and frequency related to each other? dperiod is the reciprocal of frequency.