PPolySim OS

Elastic Collisions

Balls of different masses collide and exchange momentum. At perfect restitution, total kinetic energy is conserved; below it, energy dissipates.

Elastic CollisionsLive

Controls

Presets

Balls collide with impulse-based physics. At restitution 1, kinetic energy is conserved; below 1, collisions are inelastic and energy drains away.

▶ Run in Python

Data Inspector

Balls12
Total KE0.00e+0
Collisionselastic

Governing equation

Reading this result: With restitution 1 every bounce is perfectly elastic, so the total kinetic energy of all 12 balls stays constant forever — a 2D model of an ideal gas.

Runs locally in your browser — free forever. Scale to the cloud when reality gets heavy.

or unlock everything with Pro →
★ Sign in to save this setup
Save your tuned setup, or drop this simulation into your own site, docs, or course page.

How it works

Every collision is resolved with impulse-based physics that conserves momentum, and (at restitution 1) kinetic energy. It's the core of billiards, particle physics demos, and game engines — and a clean way to see conservation laws hold in real time.

Ask the AI about this model

The math, the assumptions, real-world uses, or a code translation — explained for this exact simulation.

More Physics simulations

Frequently asked questions

Is this collision simulation tool really free?
Yes. Elastic Collisions runs entirely in your browser using your device's own compute, so local use is free forever. You only pay Compute Tokens if you scale a job to the cloud.
Do I need to install anything?
No. Everything runs client-side in a modern browser — no downloads, no license, no account required to start.
Can I save or share my simulation?
Create a free account to save projects, and use a shareable embed or minted DOI to publish a live, interactive version anywhere.
How accurate are the results?
The solver uses established numerical methods, but results are for research and educational purposes and should be validated against experiment or professional review before you rely on them.