Collision analysis
Vehicle Collision Momentum Calculator
Resolve pre-impact velocity from vehicle masses, headings, and established post-impact motion in one or two dimensions.
Conservation relationship
Σ(m × velocity)before = Σ(m × velocity)after
Momentum is a vector. In an angled collision, resolve each velocity into consistent x and y components before solving.
Florida / FHP worksheet notation
Florida training examples commonly use loaded vehicle weights, pre-impact speeds S₁ and S₂, post-impact speeds S₃ and S₄, and approach/departure angles. CrashCompute's 2D worksheet uses the same component method and familiar W₁/W₂ and S₁-S₄ notation.
A 2021 University of South Florida case study based on a Florida Highway Patrol investigation obtained hand-calculated impact speeds within a few tenths of a mile per hour of the reconstruction software result. The paper also demonstrates why repeated angle measurements matter in an angular momentum solution.
See the Florida / FDOT worked example and source notes.
Required support
- Defensible vehicle masses, including relevant occupants or load.
- Post-impact departure headings and speeds.
- A consistent coordinate system and angle convention.
- Consideration of external impulse during the collision interval.
Momentum cannot supply a unique answer when the available evidence leaves more unknowns than independent equations.
Related tools
Collinear momentum · Post-impact speed from final rest · Crush energy