What term is not the same as energy, but means the energy per unit charge?
mass
frequency
speed
voltage
The second equation is equivalent to the first. Voltage is not the same as energy. Voltage is the energy per unit charge. Thus a motorcycle battery and a car battery can both have the same voltage (more precisely, the same potential difference between battery terminals), yet one stores much more energy than the other since ΔPE = qΔV . The car battery can move more charge than the motorcycle battery, although both are 12 V batteries.