Momentum
Momentum p = mv: quantity of motion. Conserved in closed systems. Impulse J = FΔt equals change in momentum. Elastic collisions conserve KE; inelastic lose KE to heat and deformation.
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p = mv; vector quantity with direction J = FΔt = Δp (impulse-momentum theorem) Elastic: KE conserved; inelastic: KE lost Coefficient e = (v₂′-v₁′)/(v₁-v₂)
Ready to run the numbers?
Why: Momentum conservation predicts collision outcomes. Impulse explains how force over time changes motion. Essential for ballistics, vehicle safety, and sports physics.
How: p = mv for single object. For collisions: Σp_before = Σp_after. Elastic: use 1D formulas for v₁′, v₂′. Inelastic: common final velocity v′ = Σp/Σm.
Run the calculator when you are ready.
📚 Real-World Momentum Scenarios
Select a pre-configured example to explore momentum and collision physics:
For educational and informational purposes only. Verify with a qualified professional.
🔬 Physics Facts
Billiard balls demonstrate near-perfect elastic collisions
— Physics Classroom
Car crashes are inelastic; KE converts to sound, heat, deformation
— HyperPhysics
Rocket propulsion uses conservation of momentum
— MIT OCW
Bat hitting ball applies impulse, changing momentum in milliseconds
— Khan Academy
⚙️ Momentum Parameters
Calculation Mode
Object 1 Properties
Unit Settings
📊 Momentum Analysis Results
📈 Momentum Analysis Dashboard
🎱 Momentum Comparison
Before and after momentum analysis
⚡ Energy Distribution
Kinetic energy conservation analysis
🚀 Velocity Changes
Before and after velocities
🎯 Collision Elasticity
Coefficient of restitution (e)
📝 Step-by-Step Solution
Calculation Mode: BASIC MOMENTUM
Using momentum formula: p = m × v
p = 10.00 kg × 5.00 m/s
→ p = 50.0000 kg·m/s
Kinetic Energy: KE = ½mv²
KE = 0.5 × 10.00 × (5.00)²
→ KE = 125.0000 J
Kinetic Energy Before:
→ KE_before = 125.0000 J
Kinetic Energy After:
→ KE_after = 125.0000 J
🌍 Momentum Reference Guide
| Object | Momentum (kg·m/s) | Comparison |
|---|---|---|
| 🚶Walking Person (70kg) | 98.0 | 2.0x less |
| 🏃Sprinting Athlete | 700.0 | 14.0x less |
| 🚴Bicycle + Rider | 400.0 | 8.0x less |
| 🚗Car at 60 km/h | 25000.0 | 500.0x less |
| 🔫Bullet (9mm) | 4.8 | 10.4x more |
| ⚾Baseball Pitch | 6.5 | 7.7x more |
| 🚂Freight Train | 5.0e+7 | 1.0e+6x less |
| ✈️Commercial Jet | 2.0e+7 | 400000.0x less |
📋 Key Takeaways
- • Momentum (p = mv) is a vector quantity representing the quantity of motion
- • Conservation of momentum applies to all collisions in closed systems
- • Impulse (J = FΔt) equals the change in momentum
- • Elastic collisions conserve both momentum and kinetic energy
- • Inelastic collisions conserve momentum but lose kinetic energy
💡 Did You Know?
📖 What is Momentum?
Momentum is a fundamental concept in physics representing the "quantity of motion" an object possesses. It's defined as the product of an object's mass and velocity, making it a vector quantity with both magnitude and direction.
🎱 Key Properties
- • Symbol: p (lowercase)
- • Formula: p = mv
- • SI Unit: kg·m/s or N·s
- • Type: Vector (has direction)
⚡ Conservation Law
- • Total momentum in closed systems is conserved
- • Applies to all collision types
- • Fundamental law of nature
- • Valid in classical and quantum mechanics
Unlike energy, momentum is always conserved in collisions (assuming no external forces). This makes it incredibly useful for analyzing impacts, explosions, and rocket propulsion.
🧮 How to Calculate Momentum
Basic Momentum
Example: A 10 kg object moving at 5 m/s
p = 10 × 5 = 50 kg·m/s
Impulse-Momentum Theorem
Impulse equals the change in momentum and can be calculated from force and time.
Collision Equations
Conservation:
m₁v₁ + m₂v₂ = m₁v₁' + m₂v₂'
Elastic (1D):
v₁' = ((m₁-m₂)v₁ + 2m₂v₂)/(m₁+m₂)
Perfectly Inelastic:
v' = (m₁v₁ + m₂v₂)/(m₁ + m₂)
Coefficient of Restitution:
e = (v₂' - v₁')/(v₁ - v₂)
💥 Types of Collisions
Elastic Collision
e = 1 (perfect bounce)
- • Both momentum AND energy conserved
- • Objects bounce apart
- • Example: Billiard balls, atomic collisions
- • No energy lost to heat/sound
Inelastic Collision
0 < e < 1
- • Momentum conserved, energy NOT
- • Some energy lost to deformation
- • Example: Car crashes, most real collisions
- • Objects may separate or stick
Perfectly Inelastic
e = 0 (objects stick)
- • Maximum kinetic energy loss
- • Objects stick together after impact
- • Example: Bullet lodging in target
- • Common velocity after collision
📐 Momentum Formulas Reference
| Formula | Variables | Description |
|---|---|---|
| p = mv | m = mass, v = velocity | Basic momentum definition |
| J = FΔt | F = force, Δt = time interval | Impulse from force |
| J = Δp = mΔv | Δp = change in momentum | Impulse-momentum theorem |
| Σp_before = Σp_after | Closed system | Conservation of momentum |
| KE = ½mv² | m = mass, v = velocity | Kinetic energy for comparison |
🔗 Related Calculators
❓ Frequently Asked Questions
What is momentum and how is it conserved?
Momentum (p = mv) is the product of mass and velocity, a vector quantity. Conservation of momentum states that in a closed system with no external forces, total momentum before equals total momentum after: Σp_before = Σp_after. This fundamental principle applies to all collisions and interactions.
What is the difference between elastic and inelastic collisions?
Elastic collisions conserve both momentum and kinetic energy - objects bounce apart. Inelastic collisions conserve momentum but lose kinetic energy - objects stick together or deform. Perfectly inelastic collisions have maximum energy loss, with objects moving together after collision.
How do I calculate impulse?
Impulse (J) equals the change in momentum: J = Δp = FΔt, where F is average force and Δt is time interval. Impulse can also be calculated as J = mΔv. Impulse-momentum theorem states that impulse equals the change in momentum, useful for analyzing collisions and impacts.
What is the coefficient of restitution?
Coefficient of restitution (e) measures collision elasticity: e = (v₂' - v₁')/(v₁ - v₂), where primes indicate final velocities. e = 1 for perfectly elastic collisions, e = 0 for perfectly inelastic collisions. Values between 0 and 1 represent partially elastic collisions.
How does momentum relate to force?
Force equals the rate of change of momentum: F = dp/dt = d(mv)/dt. For constant mass, F = ma. Impulse (FΔt) equals change in momentum. This relationship connects Newton's laws to momentum conservation and is fundamental to understanding collisions and motion.
Can momentum be negative?
Yes! Momentum is a vector quantity, so it has direction. Negative momentum simply means motion in the opposite direction from the positive reference direction. In one-dimensional problems, negative values indicate motion in the negative direction. The magnitude is always positive.
What does "HIGH", "MODERATE", and "LOW" mean in the Bloomberg Terminal risk indicator?
The Bloomberg Terminal risk indicator categorizes momentum levels: "HIGH" (p > 10,000 kg·m/s) indicates very high momentum requiring significant safety measures, typical of vehicles, projectiles, or large moving objects. "MODERATE" (100 < p ≤ 10,000 kg·m/s) represents typical momentum for sports, machinery, or medium objects. "LOW" (p ≤ 100 kg·m/s) indicates small momentum for everyday objects or low-speed interactions.
How do I analyze two-dimensional collisions?
For 2D collisions, resolve momentum into x and y components. Conservation applies separately: Σp_x,before = Σp_x,after and Σp_y,before = Σp_y,after. Use vector addition for total momentum. Requires solving simultaneous equations for final velocities in both directions.
📚 Official Data Sources
Comprehensive momentum tutorials and examples
Momentum concepts and formulas
Momentum conservation and impulse
University-level physics courses
Standard university physics textbook
⚠️ Disclaimer
This calculator is for educational and physics analysis purposes. Momentum calculations assume idealized conditions and may vary in real-world collisions. Actual collisions involve friction, deformation, heat generation, and other energy losses not accounted for in simplified models. Coefficient of restitution varies with impact speed and material properties. For safety-critical applications (automotive safety, sports equipment, impact analysis), consult professional engineers and conduct physical testing. Always use appropriate safety margins.
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