Intermediate

Elastic Collisions

Explore the fundamental principles of momentum and energy conservation through interactive collision simulations.

Momentum ConservationEnergy Conservation1D CollisionsPhysics Simulation

Ball 1 (Blue)

Momentum: 50.0 kg·m/s

Kinetic Energy: 1250.0 J

Ball 2 (Red)

Momentum: 30.0 kg·m/s

Kinetic Energy: 450.0 J

Environment

Elastic Collision Theory

Conservation of Momentum

In any collision, total momentum is conserved:

m₁v₁ᵢ + m₂v₂ᵢ = m₁v₁f + m₂v₂f

Conservation of Kinetic Energy

In elastic collisions, kinetic energy is also conserved:

½m₁v₁ᵢ² + ½m₂v₂ᵢ² = ½m₁v₁f² + ½m₂v₂f²

Final Velocities (1D)

For one-dimensional elastic collisions:

v₁f = ((m₁ - m₂)v₁ᵢ + 2m₂v₂ᵢ) / (m₁ + m₂)
v₂f = ((m₂ - m₁)v₂ᵢ + 2m₁v₁ᵢ) / (m₁ + m₂)

Key Observations

  • When equal masses collide head-on, they exchange velocities
  • A light ball bounces back when hitting a heavy stationary ball
  • A heavy ball continues forward when hitting a light stationary ball
  • Total momentum and kinetic energy remain constant throughout

Learning Objectives

  • Understand conservation of momentum in isolated systems
  • Observe conservation of kinetic energy in elastic collisions
  • Analyze how mass ratios affect collision outcomes
  • Apply collision formulas to predict final velocities
  • Explore special cases: equal masses, stationary targets

💡 Experimentation Tips

  • Equal Masses: Set both masses to the same value and observe velocity exchange
  • Heavy vs Light: Try m₁ = 5kg, m₂ = 0.5kg to see dramatic effects
  • Head-on Collision: Set opposite velocities for classic collision scenario
  • Add Gravity: Enable gravity to see parabolic trajectories after collision
  • Watch Conservation: Monitor total momentum and KE - they should stay constant!

🌍 Real-World Applications

Billiards & Pool

Ball collisions approximate elastic collisions, allowing players to predict ball trajectories.

Particle Physics

Collision experiments in particle accelerators use these principles to study subatomic particles.

Molecular Dynamics

Gas molecules collide elastically, helping explain temperature and pressure in thermodynamics.

Vehicle Safety

Understanding collision physics helps design safer cars and predict crash outcomes.