Math Playground
Physics

Energy & work

W = F·d. Push something through a distance — and you've done work.

Work is done when a force pushes something through a distance.

Try this
5
work W = F · d (F = 50 N) = 250
Work

Only the component of force along the displacement does work. Push perpendicular to the motion and W = 0; measured in joules (J).

Your turn

You lift a 10 kg box 2 m straight up (g ≈ 9.8). How much work do you do against gravity?

Work done on an object equals the change in its kinetic energy — that's the work–energy theorem, W = ΔKE.

Work

Hold a heavy book still — your arm gets tired, but you do zero physics-work because nothing moves.