The integral represents the area under the curve between x 1 and x 2. On a graph of force as a function of position, the total work done by the force is represented by the area under the curve between the initial and final positions.
In mechanics we can also express power in terms of force and velocity. Suppose that a force F acts on a body while it undergoes a vector displacement s. If F // is the component of F tangent to the path (parallel to ∆s), then the work done by the force is ∆W = F // ∆s. the average power is Instantaneous power P is the limit of this expression as t approaches to zero