Elastic Collision Calculator
Elastic collision calculator works out Momentum and Impulse from Mass, Velocity and Final velocity. The default figures on this page give impulse of 20 N s; change any entry and the result, the working and the sources update together.
Your figures
Updates as you typeHow this is worked out
2 steps
- J = F dt = 10 x 2 = 20 N s
- By the impulse-momentum theorem, that impulse equals the change in momentum.
Its 4 worked examples are re-run on every release, last on 15 September 2026. What changed
Sources and references
3 sources
What the elastic collision calculator calculates
Computes momentum from mass and velocity, and the impulse a force delivers over a time interval, which equals the change in momentum.
How to use this elastic collision calculator
Enter Mass, Velocity, Final velocity and Force. Momentum updates as you type, and “Use a worked example” loads checked figures you can adjust. Change one figure at a time to see what drives the result.
How the result is worked out
Open “How this is worked out” beside the result for the step-by-step calculation behind Momentum, Impulse and Change in momentum.
The method follows Newtonian mechanics: v = dx/dt, F = ma, J = F dt = dp, and the work-energy relations, BIPM, The International System of Units (SI Brochure) and Impulse-momentum theorem: J = F dt = dp.
Research R3527-GT-1: 10 N for 2 s example
With Force: 10, Duration: 2, the calculator returns Impulse: 20, Change in momentum: 20. This example is checked against an independent source in the test suite.
What you can compare
Change one input at a time to see how it affects Momentum, Impulse and Change in momentum. The inputs you can vary are Mass, Velocity, Final velocity, Force and Duration.
Results are general information, not financial, tax, legal, medical or engineering advice. Check any decision that matters with a qualified professional.
See something wrong? Report a problem with this calculator
Frequently asked questions
What is the formula for a perfectly elastic collision?
On the figures this page opens with — force 10 N and duration 2 s — the impulse is 20 N s. No single number fits everyone: change any figure above and the answer updates as you type, with each step of the arithmetic beside it.
How do I calculate the speed of a collision?
Computes momentum from mass and velocity, and the impulse a force delivers over a time interval, which equals the change in momentum. Open “How this is worked out” beside the result to see each step for your own figures.
How to determine if a collision is elastic?
It needs Mass, Velocity, Final velocity, Force and Duration. Nothing else is required, and the figures stay in your browser.
How to calculate elastic collision?
The result gives Momentum, Impulse, Change in momentum, Average force and Final momentum, each labelled with its unit so the figure can be read on its own.
What are the formulas for v1 and v2 in an elastic collision?
The page opens with worked default figures: impulse of 20 N s. Replace them with your own and every figure updates as you type.
What information do I need for the elastic collision calculator?
You need Mass, Velocity, Final velocity, Force and Duration. The page opens with default figures that give impulse of 20 N s, so you can see the scale before entering your own.