What is work defined as in physics?

In physics, work is defined as the transfer of energy that occurs when a force is applied to an object and the object moves in the direction of that force. This definition is specifically tied to the interaction of the force and the movement of the object, where work is calculated by the formula: work = force × distance × cos(θ), where θ is the angle between the force and the direction of movement.

In this context, because the force works on a moving object, it results in the transfer of energy. Therefore, applying force to an object that is already in motion exemplifies how work is performed; it leads to either an increase in the object's energy or a change in its motion. Emphasizing the requirement of movement is crucial because if an object does not move, no work is done, regardless of the force applied.

Understanding this helps clarify how energy is related to mechanical processes and the significance of movement in the context of work in physics. The other options either do not encompass the requirement for movement or misdefine work, which is why they are not correct.