Identify work
Compare forces parallel, opposite, and perpendicular to a displacement.
AP Physics 1 · Unit 3 · Work, Energy, and Power
Work and Kinetic Energy
Change a force and its direction, measure the resulting motion, and connect net work with the change in kinetic energy.
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Learn by doing
Three ideas you’ll put into motion
Connect work and speed
Use the net work to predict a change in kinetic energy.
Test the relationship
Compare simulation measurements with an energy-based prediction.
The big idea
The key ideas, at a glance.
Work depends on direction
For a constant force, W = Fd cos θ. Only its component along the displacement contributes to work.
Net work changes kinetic energy
The work–kinetic energy theorem gives Wnet = ΔK. Translational kinetic energy is K = ½mv2.
A quick comparison
Double an object’s speed while keeping its mass fixed.
Its translational kinetic energy becomes four times as large.
Teaching this topic?Classroom fit, AP connections, and support
- Classroom fit
- Use for a concept introduction, guided independent practice, or a projected class discussion.
- Before students begin
- Force vectors, displacement, basic trigonometry, and squared quantities.
- Built-in support
- Prepared scenes, guided prompts, and feedback on lesson questions.
- AP Physics 1 connections
- Unit 3: work, kinetic energy, and energy-based predictions.
- Check for understanding
- Ask why a force perpendicular to displacement does zero work on that displacement.
Ready to test your thinking?
The first scene is set up. Start the lesson and explore.