College Board-Aligned Original Notes

AP Physics 1: Algebra-Based Unit 3 Topic 2: Work

Work describes energy transfer by a force acting through a displacement.

Unit 3: Work, Energy, and Power. College Board exam weighting listed for this unit: 18%-23% of multiple-choice exam score.

What to Know

Only the component of force parallel to displacement does work.
Positive work increases kinetic energy, while negative work decreases it.
A force perpendicular to displacement does no work in the simple constant-force model.
Always connect this topic back to the larger unit: Work, Energy, and Power.

Detailed Notes

Work belongs to Unit 3: Work, Energy, and Power. Work describes energy transfer by a force acting through a displacement. Start by naming the system, choosing axes or a sign convention when needed, and identifying which physical quantity is changing.

Key relationships: Only the component of force parallel to displacement does work. Positive work increases kinetic energy, while negative work decreases it. A force perpendicular to displacement does no work in the simple constant-force model.

Model to use: Resolve the force into components and identify the component along the displacement. A strong model should include labels, directions, units, and the reason each relationship applies.

AP-style move: For graph problems, area under a force-position graph represents work. For free-response work, write the principle first, show the setup, and then interpret the result in the physical context.

Key Vocabulary

Mechanical work

Energy transferred when a force acts over a displacement.

Force component

The part of a force along a chosen direction.

Positive work

Work that transfers energy into an object's kinetic energy.

Negative work

Work that removes kinetic energy from an object.

Force-position graph

A graph whose area can represent work done by a force.

Quick Practice

How would you explain Work in one or two AP-style sentences?

Name the concept, apply it to a specific example or source, and explain the reasoning that connects the evidence to your answer.

Official Alignment

Reference and Attribution

AP Physics 1 concept reference: AP Physics 1: Concise Summary Notes by IITian Academy. EduCompanion used this source as a topic checklist and conceptual reference, then rewrote the study notes in original wording.

AP Physics 1: Concise Summary Notes