What is defined as the ability to do work?

The definition of energy is the capacity or ability to do work. In physics, energy exists in various forms such as kinetic, potential, thermal, chemical, and others, and it can be converted from one form to another but never created or destroyed. When we talk about doing work, we are referring to the transfer of energy through force applied over a distance, which highlights the relationship between energy and work.

Other terms like force and power are related but do not define this concept correctly. Force is an influence that causes an object to undergo a change in speed, direction, or shape, while power refers to the rate at which work is done or energy is transferred over time. Work rate implies the speed at which work is performed, which again centers more around the action of work rather than the ability itself. Thus, energy is the key concept that embodies the ability to perform work.