Compare rates
Observe equal amounts of work completed over different elapsed times.
AP Physics 1 · Unit 3 · Work, Energy, and Power
Power and Energy Transfer
Compare how quickly work is done, then connect force, speed, and energy-transfer rate in a guided simulation.
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Learn by doing
Three ideas you’ll put into motion
Calculate average power
Use energy transfer and total time to compare two processes.
Connect force and speed
Explain how motion affects the rate of work by a force.
The big idea
The key ideas, at a glance.
Power measures a rate
Average power is Pavg = ΔE/Δt for the energy transferred. For work, use W/Δt. A watt is one joule per second.
Instantaneous power follows motion
For a force acting on a moving object, power depends on the component of force along velocity. For parallel force and motion, P = Fv.
A quick comparison
Complete the same work in half the time.
The average power is twice 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
- Work, energy, elapsed time, and basic division.
- Built-in support
- Prepared scenes, guided prompts, and feedback on lesson questions.
- AP Physics 1 connections
- Unit 3: power and rates of energy transfer.
- Check for understanding
- Ask why knowing the total work alone is not enough to determine average power.
Ready to test your thinking?
The first scene is set up. Start the lesson and explore.