Compare scale readings
Observe apparent weight during different elevator accelerations.
AP Physics 1 · Unit 2, Part 1 · Forces
Elevator Forces and Apparent Weight
Ride through elevator motion and use force diagrams to explain when a scale reads heavier, lighter, or the usual weight.
Start lesson- Free
- No account required
- Self-paced
Start guided lesson
Learn by doing
Three ideas you’ll put into motion
Separate direction and change
Distinguish moving upward from accelerating upward, including slowing during a trip.
Explain the forces
Compare the normal force with gravitational force and connect the difference to acceleration.
The big idea
The key ideas, at a glance.
The scale measures normal force
Apparent weight is the support force exerted on the rider. Gravitational force remains mg near Earth.
Acceleration sets the difference
With upward positive, N − mg = ma. An upward acceleration raises the scale reading; downward acceleration lowers it.
A quick comparison
The elevator moves upward at constant velocity.
Acceleration zeroScale reading N = mg
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
- Free-body diagrams and Newton’s second law. Keep upward and downward signs consistent.
- Built-in support
- Prepared scenes, guided prompts, and feedback on lesson questions.
- AP Physics 1 connections
- Unit 2: applying Newton’s laws to apparent weight and equilibrium.
- Check for understanding
- Ask whether an elevator moving downward must always make its rider feel lighter.
- Optional extension
- Try the Elevator Forces lab.
Ready to test your thinking?
The first scene is set up. Start the lesson and explore.