Awater wave rises and falls twice every four seconds. what is the period of the wave? what is its frequency? i would really appreciate someone walking me through how to solve this, you!

Period = 2 seconds.
frequency = 1/2 cycle/second = 1/2 Hz

If it falls twice every four seconds, then it falls once every two seconds, therefore one falling period is two seconds.

Hz is equal to cycles per second. So if it goes through one cycle per two seconds, then it goes through 1/2 cycle per one second.

Hope this helps!

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.

Ithink the answer is d