Test the model
Compare falling objects while changing mass, shape, or release height.
AP Physics 1 · Unit 1 · Kinematics
Free Fall Motion
Drop and launch objects, compare masses, and use vertical-motion graphs to predict free fall, the highest point, and landing.
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Learn by doing
Three ideas you’ll put into motion
Track an upward launch
Observe slowing, the highest point, and the return to the launch height.
Check vertical predictions
Use signed velocity, acceleration, and elapsed time to interpret graphs and calculate motion.
The big idea
The key ideas, at a glance.
Gravity sets acceleration
With air resistance ignored and upward positive, ay = −g. Mass does not change the free-fall acceleration.
The apex is an instant
Vertical velocity is zero at the highest point. Acceleration remains downward throughout the flight.
A quick comparison
Compare the highest point with a moment just before it.
At the apex: vy = 0Still: ay = −g
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
- Constant acceleration, a consistent positive direction, and basic kinematics algebra.
- Built-in support
- Prepared scenes, guided prompts, and feedback on lesson questions.
- AP Physics 1 connections
- Unit 1: vertical motion under near-Earth gravity and motion graphs.
- Check for understanding
- Ask students to explain why zero velocity at the apex does not mean zero acceleration.
- Optional extension
- Collect additional evidence in the Free Fall lab.
Ready to test your thinking?
The first scene is set up. Start the lesson and explore.