Online Tool Store
Momentum Collision Calculator
Momentum Collision Calculator conserves momentum in every case and shows the kinetic energy the inelastic case loses — which is the physically interesting.
🔒 This tool runs entirely in your browser. Your files are never uploaded to a server.
Math & Science
Momentum Collision Calculator
Frontend preview — no upload or external service.
Final velocities
Object 1: 8.33 m/s. Object 2: 5 m/s. Total momentum conserved at 50,000 kg·m/s.
How the Momentum Collision Calculator works
- Enter both masses and velocities, using signs for direction.
- Choose the collision type — elastic conserves kinetic energy, inelastic does not, and real collisions sit between them.
- Check that momentum is conserved in the output. It always is; kinetic energy is what varies.
The method
Momentum is conserved in every collision. Kinetic energy is conserved only in a perfectly elastic one.
m1u1 + m2u2 = m1v1 + m2v2
A perfectly inelastic collision loses the maximum kinetic energy consistent with conserving momentum — which in vehicle safety terms is energy going into crumple rather than into the occupants.
FAQ
Is momentum always conserved?
In an isolated system, yes — that is what makes it the useful quantity. Kinetic energy is only conserved in a perfectly elastic collision, which is why the two are treated separately.
What is a coefficient of restitution?
A number from 0 to 1 describing how elastic a collision is. Zero is perfectly inelastic with the objects moving together; one is perfectly elastic. Real collisions fall in between and it is measured, not derived.
Where does the lost energy go?
Deformation, heat and sound. In vehicle design that is the point — a structure that deforms absorbs energy that would otherwise reach the occupants.
How we compare
| Feature | Online Tool Store | A graphing calculator | A stats package |
|---|---|---|---|
| Elastic and inelastic | ✓ | One | ✓ |
| Energy loss shown | ✓ | ✗ | ✓ |
| No sign-up | ✓ | ✓ | ✗ |
| Nothing uploaded | ✓ | ✓ | ✗ |
Momentum Collision Calculator conserves momentum in every case and shows the kinetic energy the inelastic case loses — which is the physically interesting number.