Mechanics
Bouncing ball
Watch each bounce fall a little lower as energy is lost.
Bouncing ball — interactive Mechanics simulation. Watch each bounce fall a little lower as energy is lost. Free browser-based virtual physics lab with live SI measurements and a guided tutorial.
Energy loss in bounces
A bouncing ball loses mechanical energy on each impact when restitution is less than 1. Each bounce reaches a lower height.
Kinetic energy converts to potential energy at the top of each bounce, but the collision with the floor is inelastic. Restitution below 1 means the ball leaves the floor slower than it arrived, so peak height decreases each cycle.
- KE + PE = E (decreases each bounce)
- Restitution e < 1
Investigation brief
Plan the question before you open the lab
The brief mirrors the prerendered page: driving question, competing predictions, variable roles, governing laws, setup, analysis and extension prompts remain visible and in this order.
Driving question
When a ball is dropped and bounces off the floor, does it rebound to the same height it was dropped from, a higher height, or a lower height?
Predictions to weigh
- It rebounds to the same height (no energy is lost).
- It rebounds higher than the drop height.
- It rebounds lower than the drop height (some energy is lost).
Variable roles
What you set:
- Mass (kg)
- Drop Height (m)
What you measure:
- Gravitational PE (J)
- Rebound Height (1st bounce) (m)
How the investigation runs
- Open the Bouncing Ball preset. Note the ball's starting height above the floor and its mass.
- Confirm the height probe is attached to the ball — it reports the ball's height above the floor in meters.
- Run the simulation and let the ball fall and bounce. Pause at the top of the first rebound and record the peak height reached.
Governing equation
Gravitational Potential Energy — PE = m·g·h
The energy stored in the ball's height above the floor just before release — this is the energy budget available to convert into kinetic energy during the fall and, after the bounce, back into height.
Kinetic Energy — KE = ½·m·v²
The energy of the ball's motion. Just before impact, essentially all of the drop's PE has converted to KE; the bounce then returns only a fraction of that KE, which is why the rebound falls short of the drop height.
What the printable worksheet asks students to work out
- For each row, divide the rebound height by the drop height. What do you notice about this ratio across your three trials?
- The ball's restitution is 0.8. Square that value and compare it to the ratio you computed above. What relationship do you find?
Where this shows up beyond the lab
- If the height ratio you found stays constant bounce after bounce, predict the peak height of the *second* rebound for your first trial. How many bounces would it take before the peak height drops below 1 cm?
- A real dropped ball also loses a little energy to air resistance and sound on each bounce. Would you expect a real ball's rebound heights to fall off faster or slower than the idealized e² pattern you found here?
- AP Physics 1 — Unit 3: Work, Energy, and Power
- AP Physics C: Mechanics — Unit 3: Work, Energy, and Power
- IB Physics — A.3 Work, energy and power
- General High School Physics — Work, energy & power
- NGSS High School Physics — Energy accounting in systems
- Middle School Physical Science — Newton's third law and collisions
- Middle School Physical Science — Kinetic energy
- Middle School Physical Science — Energy in, energy out
- Welcome to Bouncing Ball
- Select the ball
- Press Play
- Dying bounces
- Open the data
- You did it!
Open the interactive simulation to build the scene, press Play, and explore with live measurements and a guided tutorial.