From the work-energy theorem, the workdone by a force on a body causes a change in kinetic energy of the body.
But, remember that the work done (W) by a force (F) on a body is the product of the force and the distance d, moved by the body caused by the force. i.e
W = F x d
This distance is a measure of the position of the body at a given instance.
Therefore, the work done is given by the force as a function of distance (or position).
