Collision Lab
Crash two objects together and watch what happens. Set the mass and velocity of each, choose the collision type, and see conservation of momentum in action — while kinetic energy tells a different story depending on whether the collision is elastic or inelastic.
Collision Simulation
The Physics Behind This Simulation
Every collision obeys Newton's third law: the forces the two objects exert on each other are equal and opposite. This guarantees conservation of momentum. Whether kinetic energy is also conserved depends on the type of collision.
The coefficient of restitution e measures how "bouncy" a collision is. For a perfectly elastic collision e = 1 and no kinetic energy is lost. For a perfectly inelastic collision e = 0 and the objects stick together, losing the maximum possible kinetic energy while still conserving momentum. Real collisions fall somewhere in between.
Things to Try
Equal masses, elastic
Set both masses to 2 kg with opposite velocities. After an elastic collision, the objects swap velocities — a hallmark of equal-mass elastic collisions.
Car hits bike
Set A to 1500 kg at 30 m/s and B to 15 kg at 0 m/s. Watch the massive car barely slow down while the light bike flies away — real-world momentum transfer.
Perfectly inelastic
Switch to e = 0. The objects stick together and move as one. Compare the KE lost — it's the maximum loss that still conserves momentum.
Same direction, different speeds
Set both velocities positive (e.g., A = 50, B = 10). Object A catches up to B — a rear-end collision. Momentum is still conserved.