What is the definition of work in mechanics?

Work in mechanics is defined as the amount of energy needed to move an object a distance while applying a force. This definition emphasizes two key components: the application of a force and the movement of the object over a distance. To calculate work, you multiply the force applied to the object by the distance the object moves in the direction of the force. If there is no movement, or if the force is applied at an angle that does not contribute to the movement, then no work is done.

For instance, if you push a box across the floor, the force you apply over the distance the box is pushed constitutes work. Conversely, if you exert a force on an object but it does not move—like pushing against a wall—no work is accomplished, even though force is being applied.

Understanding this concept is crucial in mechanics because it relates directly to energy transfer, moving from one form to another, such as from potential energy to kinetic energy or vice versa.