What is the unit of energy in the International System of Units (SI)?

The unit of energy in the International System of Units (SI) is the Joule (J). The Joule is defined as the amount of work done when a force of one newton is applied over a distance of one meter. It is a standard unit that quantifies energy, work, and heat.

Understanding the Joule as the official SI unit of energy is essential in various fields, including physics, engineering, and heat transfer, because it provides a consistent measurement system that is globally recognized and used in scientific calculations.

In contrast, other options such as the Calorie (cal) are units used primarily in specific contexts, especially in chemistry and nutrition, to measure heat energy, but they are not part of the SI system. The Watt (W) represents power, which is defined as the rate of energy transfer over time, while the Newton (N) is a unit of force. Therefore, the Joule stands out as the appropriate choice for measuring energy within the SI framework.