# Work Done On or By The System

by brentd49
Tags: work
 Sci Advisor HW Helper PF Gold P: 562 Work is always associated with a particular force. The work done by the force is: $$W = \int \vec{F}.d\vec{r}$$ In your example of lifting an object, the work done by the gravitational force is negative, while the work done by the lifting force is positive.