Conservation of Momentum Calculator

Analyze collisions and momentum conservation in two-object systems

Collision Parameters

Object 1

Object 2

Momentum Conservation Results

12.000
m/s
FINAL V2

Momentum Conservation

Initial: 80.000 kg⋅m/s
Final: 80.000 kg⋅m/s
✓ Conserved

Kinetic Energy

Initial: 400.000 J
Final: 352.000 J
Loss: 48.000 J (12.0%)

Collision Type Analysis

Partially Elastic
Momentum conserved, some kinetic energy lost

Conservation Formula: m₁u₁ + m₂u₂ = m₁v₁ + m₂v₂

Total momentum must be conserved in isolated systems with no external forces

Example Calculation

Billiard Ball Collision

Object 1: Mass = 8 kg, Initial velocity = 10 m/s

Object 2: Mass = 4 kg, Initial velocity = 0 m/s (at rest)

After collision: Object 1 slows to 4 m/s

Find: Final velocity of object 2

Solution Steps

1. Initial momentum: p₁ = 8 kg × 10 m/s + 4 kg × 0 m/s = 80 kg⋅m/s

2. Final momentum of object 1: p₁f = 8 kg × 4 m/s = 32 kg⋅m/s

3. Required momentum for object 2: p₂f = 80 - 32 = 48 kg⋅m/s

4. Final velocity of object 2: v₂f = 48 kg⋅m/s ÷ 4 kg = 12 m/s

Answer: Object 2 moves at 12 m/s after collision

Types of Collisions

Perfectly Elastic

Both momentum and kinetic energy conserved

Example: Billiard balls, gas molecules

Partially Elastic

Momentum conserved, some KE lost

Example: Car crashes, most real collisions

Perfectly Inelastic

Objects stick together after collision

Example: Bullet hitting wooden block

Real-World Examples

Gun Recoil

Bullet forward → Gun backward

Rocket Propulsion

Hot gas expelled → Rocket moves forward

Ice Skaters

Push apart → Move in opposite directions

Pool/Billiards

Cue ball transfers momentum to target ball

Physics Tips

Momentum is always conserved in isolated systems

Kinetic energy is only conserved in elastic collisions

Total energy is always conserved (includes heat, sound)

Momentum is a vector quantity (has direction)

Understanding Conservation of Momentum

The Fundamental Principle

The law of conservation of momentum states that in an isolated system (no external forces), the total momentum before collision equals the total momentum after collision. This is one of the most fundamental principles in physics.

Mathematical Formula

m₁u₁ + m₂u₂ = m₁v₁ + m₂v₂

where:

m = mass, u = initial velocity, v = final velocity

subscripts 1,2 refer to objects 1 and 2

Key Concepts

  • Momentum: Product of mass and velocity (p = mv)
  • Isolated System: No external forces acting on the system
  • Vector Quantity: Momentum has both magnitude and direction
  • Newton's Laws: Conservation follows from Newton's third law

Remember: Momentum is always conserved, but kinetic energy is only conserved in perfectly elastic collisions. In real-world scenarios, some energy is usually converted to heat, sound, or deformation.

Types of Collision Analysis

Elastic Collision

Both momentum and kinetic energy are conserved. Objects bounce off each other completely.

Examples: Billiard balls, gas molecules

Inelastic Collision

Momentum is conserved but kinetic energy is lost to other forms like heat and sound.

Examples: Car crashes, clay balls

Perfectly Inelastic

Objects stick together after collision and move with common velocity.

Examples: Bullet in wood, train coupling