Work

Force times distance, in the right direction

An interactive lesson with 8 steps, about 7 minutes: you predict, drag and solve, with instant feedback on every answer. It runs in your browser and needs JavaScript.

What you’ll learn

• Work $W = Fd\cos\theta$, measured in joules (J = N·m).
• Forces perpendicular to the motion do no work. Forces against the motion do negative work.
• Lifting a mass $m$ through a height $h$ takes $W = mgh$.

Steps

1. Tired arms
2. What work means
3. Push the crate
4. Lift the book
5. At an angle
6. Negative work
7. Pulling at an angle
8. Up the stairs