Explore the Collision Lab: 2D Momentum & Kinetic Energy
Crash balls of different masses on a table and track total momentum and kinetic energy for bouncy or sticky collisions. Works on phones and computers.
- Free to use
- No signup
- Nothing to install
- Runs in your browser
Illustration. Open the tool for the real thing.
See it in action
The Collision Lab: 2D Momentum & Kinetic Energy with sample data entered and the result showing.
What is the Collision Lab: 2D Momentum & Kinetic Energy?
Crash balls of different masses on a table and track total momentum and kinetic energy for bouncy or sticky collisions. It runs in your browser, so a change to a setting or a drag on an object shows up at once.
Car safety design, billiards, particle physics and crash reconstruction all rely on conservation of momentum.
3 steps to your result
Open the tool and follow along. Nothing to install.
What you get
Total momentum stays the same in every collision when no outside force acts.
In a perfectly elastic collision kinetic energy is also conserved.
In an inelastic collision some kinetic energy turns into heat and sound, but momentum is still conserved.
Set elasticity to 1 and watch the energy lost readout stay at zero.
Set elasticity to 0 and see how much energy disappears.
Give a light ball a big speed and hit a heavy ball.
Used for
Pick one to see how it fits.
Physics learners
Physics students in middle school, high school and first-year university, teachers who want a quick demonstration for the projector, and anyone revising for exams.
Try it freeTeachers
For teachers: project the Collision Lab: 2D Momentum & Kinetic Energy on the board, let students predict the result, then run it together and test this: Set elasticity to 0 and see how much energy disappears. For students: change one thing at a time and write down what changes.
Try it freeHow it compares
A plain look at this tool next to the usual alternative.
| This simulation | Textbook diagram | |
|---|---|---|
| Interactive | Drag, tap and change settings | Fixed picture |
| Install | Nothing to install | Not needed |
| Cost | Free to use | Depends on the book |
Questions people ask
What is the difference between elastic and inelastic collisions?
Elastic collisions keep the total kinetic energy. Inelastic ones lose some. Momentum is conserved in both.
Why does the center of mass not change speed?
There is no net outside force on the group of balls, so their center of mass moves at a steady velocity.
Is the Collision Lab: 2D Momentum & Kinetic Energy free to use?
Yes. The Collision Lab: 2D Momentum & Kinetic Energy is free, needs no signup or download and runs in your web browser. It is part of the Physics group of AZRS simulations.
Does the Collision Lab: 2D Momentum & Kinetic Energy work on a phone or tablet?
Yes. The Collision Lab: 2D Momentum & Kinetic Energy takes touch input as well as mouse input, so you can use its 6 adjustable settings with a finger. A larger screen makes the controls and graphs easier to read.
How do I use the Collision Lab: 2D Momentum & Kinetic Energy?
1. In the Collision Lab: 2D Momentum & Kinetic Energy, use the controls to change Red ball mass, Blue ball mass, Green ball mass, Elasticity, Balls, and more. The simulation reacts instantly. 2. In the Collision Lab: 2D Momentum & Kinetic Energy, pick an option such as 2 balls, 3 balls, Bounce off walls, Wrap around to switch modes or load an example. 3. In the Collision Lab: 2D Momentum & Kinetic Energy, press "Pause", "Reset" to start, reset or change what is happening. 4. Start with this experiment: Set elasticity to 1 and watch the energy lost readout stay at zero. Drag any glowing handle, object or slider with your mouse or finger and the Collision Lab: 2D Momentum & Kinetic Energy responds in real time. 5. Change one setting at a time and watch which readout moves, then compare it with this idea: Total momentum stays the same in every collision when no outside force acts.
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Try the Collision Lab: 2D Momentum & Kinetic Energy now
Crash balls of different masses on a table and track total momentum and kinetic energy. Free to use.
Try it free