In Newtonian mechanics, work is a measure of energy expended in applying force over a distance.
For the motion of a body against a constant force, work can be expressed as:
 W = F · d (dot product)

 W : work (energy)
 F : force
 d : distance moved
The SI derived unit of work is the Joule. Other units include the erg, the footpound, and the footpoundal.