Work

Science

Definition

In physics, work is done when a force causes an object to move in the direction of that force. If you push a box across the floor, you do work on it; if you push against a wall and nothing moves, no work is done. Work is a scalar quantity measured in joules.

Examples

  • Lifting a 10 kg textbook 1.5 meters onto a shelf (W = mgh ≈ 147 J)
  • A person pushing a grocery cart 20 meters through a store with a constant force
  • Gravity doing work on a skier as they descend a slope, increasing kinetic energy
Key Fact

W = Fd cos θ, measured in joules (J). 1 J = 1 N·m.

Related Terms

Work-energy theorem Kinetic energy Potential energy Conservation of energy

Study This Concept

Practice work with free review games in these units:

Physics Unit 3: Work and Energy