Collision Lab (1D)

Set two carts moving and watch them collide. Momentum is always conserved — but dial the restitution from elastic to perfectly inelastic and watch kinetic energy vanish into heat.

Collision Lab (1D)Live

momentum is always conserved

Controls

Presets

Mass 1 (kg)

Mass 2 (kg)

Velocity 1 (m/s)

Velocity 2 (m/s)

Restitution e

Momentum is conserved in every collision. Kinetic energy is conserved only when e=1 (perfectly elastic); at e=0 the carts stick together and the lost energy becomes heat and sound. Drag either cart on the canvas to set where it starts.

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Data Inspector

Final v₁0.33 m/s

Final v₂4.33 m/s

KE before9.5 J

KE after9.5 J

Energy lost0%

Governing equation

v_{1}^{'} = \frac{m _{1} u _{1} + m _{2} u _{2} - m _{2} e ( u _{1} - u _{2} )}{m _{1} + m _{2}} = 0.33, v_{2}^{'} = \frac{m _{1} u _{1} + m _{2} u _{2} + m _{1} e ( u _{1} - u _{2} )}{m _{1} + m _{2}} = 4.33

Reading this result: This collision is elastic (e=1), so kinetic energy is fully conserved; momentum-sharing only redistributes the speeds between the two masses.

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How it works

One-dimensional collisions conserve momentum: m₁u₁ + m₂u₂ = m₁v₁ + m₂v₂. The coefficient of restitution e sets how much relative speed survives: e=1 conserves kinetic energy (elastic), e=0 makes the carts stick (perfectly inelastic). Real collisions fall in between. Educational tool.

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Frequently asked questions

Is this elastic inelastic collision simulator tool really free?▾

Yes. Collision Lab (1D) 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.