Physics Collisions

Conservation of Momentum — Collisions

Apply conservation of momentum to elastic and perfectly inelastic collisions. Computes final velocities, kinetic energy before and after, and energy lost.

Perfectly inelastic
Elastic collision
ΔKE = KE_after − KE_before
Live
Inputs
Object 1
Positive = rightward. Negative = leftward.
Object 2
Results
Final Velocity
p before (kg·m/s)
p after (kg·m/s)
Conserved?
KE before (J)
KE after (J)
ΔKE lost (J)
Step-by-Step Solution
Before & After Collision Diagram
Conservation of Momentum
m₁v₁ + m₂v₂ = m₁v₁' + m₂v₂'

In an isolated system (no external forces), total momentum is conserved in all collision types. For perfectly inelastic: objects stick together (v₁' = v₂' = v_f).

Elastic vs Inelastic
Elastic: KE conserved; Inelastic: KE lost

Elastic: both momentum and KE conserved. Perfectly inelastic: momentum conserved, maximum KE lost. Real collisions are somewhere between.

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