Which of the following statements is true regarding work?

Work in the context of physics is defined as the product of the force applied to an object and the distance over which that force is applied, specifically when the force and the movement of the object occur in the same direction. Therefore, for work to be done, there must be both a force acting on an object and that object must move as a result of that force. This definition makes it clear that movement and force are essential components for completing any work.

The other statements do not hold true within the framework of this definition. Work can be performed without machines, rather than exclusively relying on them, and while work is closely associated with motion, it is not independent of it—motion is a critical element of the work equation. Lastly, work is not classified as a chemical quantity; it belongs to the realm of physics as a measure of energy transfer, not a property of chemical reactions. Thus, the correct understanding aligns with the statement regarding the requirement of both movement and force for work to occur.