How is the crash force calculated?

The calculator uses the impulse-momentum theorem: force equals mass times change in velocity divided by stopping time. You input vehicle mass, initial and final speeds, and stopping time to get the average force in newtons.

What units should I use?

Enter mass in kilograms (kg), speeds in meters per second (m/s), and stopping time in seconds (s). The result is the average force in newtons (N).

Can this calculator predict injury severity?

No, it only estimates the average force. Actual injury depends on many factors like seatbelt use, airbags, and crash dynamics. Always consult safety professionals for real-world assessments.

Physique

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Calculatrice: Car Crash Force.

15 oct. 2026

Utilisez Calculatrice: Car Crash Force pour obtenir un résultat clair et pratique à partir de vos données.

Cette calculatrice n'est pas encore entièrement traduite ; une partie du texte s'affiche en anglais.

Calcul sur l'appareilSans inscription

Saisissez vos valeurs

Les résultats se mettent à jour pendant la saisie.

02 / RÉPONSE

Vehicle mass

Initial speed

Final speed

Stopping time

averageForceN

300 000N

impulseNs

30 000N·s

averageAccelerationMps2

-200m/s²

Results update automatically as you type.

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Cite this calculator

Canonical URL: https://mathify.one/fr/physics/car-crash-force

Updated 15 oct. 2026

Cite as: Mathify. (2026). Calculatrice: Car Crash Force. https://mathify.one/fr/physics/car-crash-force

Use Cases

Physics homework or classroom demo

Students can quickly compute impact force for different masses, speeds, and stopping times to understand Newton's laws.

Example: A 1200 kg car decelerates from 20 m/s to 0 in 0.1 s: force = 240,000 N.

Safety design considerations

Engineers and safety enthusiasts can explore how longer stopping times reduce force, illustrating the role of crumple zones.

Example: Doubling stopping time from 0.1 s to 0.2 s halves the average force.

Frequently Asked Questions

How is the crash force calculated?: The calculator uses the impulse-momentum theorem: force equals mass times change in velocity divided by stopping time. You input vehicle mass, initial and final speeds, and stopping time to get the average force in newtons.
What units should I use?: Enter mass in kilograms (kg), speeds in meters per second (m/s), and stopping time in seconds (s). The result is the average force in newtons (N).
Can this calculator predict injury severity?: No, it only estimates the average force. Actual injury depends on many factors like seatbelt use, airbags, and crash dynamics. Always consult safety professionals for real-world assessments.

Tips & Common Mistakes

Tips

Ensure speeds are in m/s; convert from km/h by dividing by 3.6.
Use a realistic stopping time (0.1–0.3 s for a crash) for meaningful estimates.
If final speed is zero, the change in speed equals the initial speed.
Remember that this is an average force; peak forces can be higher.

Common Mistakes to Avoid

Forgetting to convert km/h to m/s, leading to incorrect force values.
Using stopping distance instead of stopping time; this calculator requires time.
Assuming the force is constant during the crash; it's an average estimate.

Last updated: August 13, 2026