Which unit is commonly used to measure energy?

Energy is commonly measured in joules, which is the standard unit in the International System of Units (SI). A joule is defined as the amount of energy transferred when a force of one newton is applied over a distance of one meter. This unit is widely used in various fields of science and engineering to quantify energy, whether it be kinetic energy, potential energy, or thermal energy.

While the other units mentioned serve important purposes in different contexts (pascals measure pressure, watts measure power, and volts measure electrical potential), they do not specifically measure energy. Watts, for instance, represent the rate at which energy is used or transferred over time, which is a different concept. Therefore, the correct answer reflects the direct measurement of energy itself.