Work is the energy transferred to or from an object as the result of the action of a force.
Positive work is a transfer of energy to the object, and negative work is a transfer of energy from the object.
Work = Force x Displacement
The unit of work is the joule*, J, which is defined as the amount of work done when a force of 1 newton acts for a distance of 1 m in the direction of the force. Thus, 1 J = 1 N m
NOTE: If the body moves in the same direction as the force the angle is 0 degree, then;
Workdone = F x d
Where d is the distance.
When the angle is 90 then the work done is zero.
FORCE – DISTANCE GRAPH
If a graph is plotted of experimental values of force(on the y-axis) against distance moved (on the x-axis), the graph is called force-distance graph or work diagram.
The area under the graph represents the work done.
A constant force F, used to raised a load of distance d, can be represented by a force – distance graph shown below;
Similarly, a spring extended by distance, d by a force F, can be represented by a force – distance graph as shown below;