What is power defined as?

Power is defined as the rate at which work is performed or energy is transferred over time. This definition emphasizes that power quantifies how quickly work is done. It is expressed in units such as watts, where one watt is equivalent to one joule of work done per second. Understanding power in this way is essential for various applications, including electrical systems, mechanical systems, and thermodynamics, as it allows engineers to calculate efficiency, energy use, and operational performance.

In contrast, while the capacity of a body or substance to perform work and the ability to exert force relate to the potential energy and mechanics involved in performing work, they don’t capture the dynamic aspect of how fast this work can be accomplished. Similarly, the concept of total energy in a system pertains to the overall energy content rather than how swiftly that energy is converted into work. Thus, defining power as the rate of doing work is crucial for accurately describing the performance of systems in power engineering.