What is work?
Work is done when a force moves.
Everyday examples of work include walking up a flight of stairs, lifting heavy objects, pulling a sledge and pushing a shopping trolley.
Work is not done when holding a bag stationary or a book at arm’s length because although a force is being applied, the force does not move.
Calculating work done
Here is the equation that relates to work done, force applied, and distance moved in the direction of the force.
\(\text{Work done} = {\text{Force}}\times{\text{distance}}\)
\(\text{W} = {\text{F}}\times{\text{d}}\)
where
W is work done measured in joules, J
F is force measured in newtons, N
d is distance measured in metres, m
In the example above, 10 N is applied to move the box 2 m.
Work done W = Fd
F = 10 N
d = 2 m
Work done = 10 Ă— 2 = 20 J
The work done pushing the box 2 m is 20 J.
Equations for calculating work
| W=Fd | W=Fxd |
| F=\(\frac{\text{W}}{\text{d}}\) | F = W Ă· d |
| d=\(\frac{\text{W}}{\text{F}}\) | d = W Ă· F |
| W=Fd |
| W=Fxd |
| F=\(\frac{\text{W}}{\text{d}}\) |
| F = W Ă· d |
| d=\(\frac{\text{W}}{\text{F}}\) |
| d = W Ă· F |