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For Students · Elastic Collisions

Elastic Collisions for a two-cart collision

Built for students learning it for a class or exam. See the concept move instead of memorizing formulas — and check your homework intuition. Simulate a two-cart collision live below — adjust the inputs and watch it respond, right in your browser.

Elastic CollisionsLive

momentum & energy conservation

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Speed1×

Presets

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

Balls

Restitution

▶ Run in Python

Data Inspector

Balls12

Total KE0.00e+0

Collisionselastic

Governing equation

j = \frac{- ( 1 + e ) ( v _{b} - v _{a} ) \cdot n ^}{1/ m _{a} + 1/ m _{b}}, e = 1.00

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.

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Frequently asked questions

Is this good for students?: Yes — this version of "Elastic Collisions for a two-cart collision" is framed for students learning it for a class or exam. See the concept move instead of memorizing formulas — and check your homework intuition.
Do I need to install anything?: No. It runs in any modern browser, free, with no account required.