What are work and power?

Work and power: W = F × d · P = W ÷ t. You do work when a force moves something along the direction it pushes: work = force × distance, measured in joules. Power is how fast you do that work, work ÷ time, measured in watts.

Read how it works: What are work and power? · The history of work and power · More boxes on Glassbox

Chapters in this interactive model

1. Work is force times distance: Pull, lift and stretch, and watch the joules pile up under a graph.
2. Stairs, pedals and horsepower: How many watts can a person, a cyclist and a horse put out?
3. Machines trade force for distance: Levers, pulleys and ramps make the push smaller, never the work.
4. Paying for work: watts, units and food: Your electricity bill and your lunch are both counted in energy.
5. When work isn’t what it seems: Carrying a bag, fast and slow lifts, braking, and tired muscles.