In physics, what does the term 'work' encompass?

The term 'work' in physics specifically relates to the process of energy transfer that occurs when an object is moved over a distance by an external force. The most common context for this is when a force acts on an object in the direction of its displacement. This means that work is done when a force causes an object to move from one point to another, which inherently involves the transfer or conversion of energy.

When considering why energy associated with moving objects is central to the definition of work, it's important to understand that kinetic energy is a fundamental concept in this context. The work-energy principle states that the work done on an object is equal to the change in its kinetic energy. Therefore, the energy involved in the motion of an object directly relates to the concept of work.

In contrast to other options, energy applied to stationary objects does not result in work since no displacement occurs. While friction does involve energy loss, it specifically relates to the energy dissipated which doesn't align with the definition of work. Lastly, only lifting objects is a specific case of work; it does not encompass the broader application of work as it applies to any situation where force causes movement. Thus, the focus on energy during the movement of objects distinctly captures the essence of work in physics