⚡ Momentum Calculator
Calculate momentum, mass, or velocity using the physics formula p = m × v. Enter any two values and the calculator will solve for the third. Perfect for physics students, engineers, and anyone working with linear momentum.
What Is Momentum?
In physics, momentum is the product of an object's mass and its velocity. It is a vector quantity, meaning it has both magnitude and direction. The standard unit of momentum is the kilogram-meter per second (kg·m/s).
Momentum is a fundamental concept in mechanics and is conserved in closed systems. The law of conservation of momentum states that the total momentum of a system remains constant if no external forces act on it.
p = m × v
Momentum (p) = Mass (m) × Velocity (v)
How to Use the Momentum Calculator
- Select what you want to calculate: Momentum (p), Mass (m), or Velocity (v).
- Enter the two known values. The calculator will solve for the missing one.
- Choose your desired decimal precision.
- Click "Calculate" to get your result.
Common Momentum Calculations
- Baseball: A 0.145 kg baseball thrown at 40 m/s has momentum of 5.8 kg·m/s.
- Car: A 1,500 kg car traveling at 20 m/s (72 km/h) has momentum of 30,000 kg·m/s.
- Bowling Ball: A 7 kg bowling ball rolling at 6 m/s has momentum of 42 kg·m/s.
- Running Person: A 70 kg person running at 4 m/s has momentum of 280 kg·m/s.
Momentum vs. Kinetic Energy
While both momentum and kinetic energy depend on mass and velocity, they are different quantities:
- Momentum (p = m·v): Linear with velocity. Doubling velocity doubles momentum.
- Kinetic Energy (KE = ½·m·v²): Quadratic with velocity. Doubling velocity quadruples kinetic energy.
❓ Momentum Calculator FAQ
What is the formula for momentum?
The formula for linear momentum is p = m × v, where p is momentum, m is mass, and v is velocity.
What are the units of momentum?
Momentum is measured in kilogram-meters per second (kg·m/s). In imperial units, it can be measured in slug-feet per second (slug·ft/s).
Is momentum a vector or scalar?
Momentum is a vector quantity , it has both magnitude and direction. The direction of momentum is the same as the direction of velocity.
What is the law of conservation of momentum?
The law of conservation of momentum states that the total momentum of a closed system (no external forces) remains constant. This is a fundamental principle in physics used to analyze collisions and explosions.
What is the difference between momentum and impulse?
Impulse is the change in momentum. It is equal to the force applied multiplied by the time over which it is applied (J = F × Δt = Δp).
Can momentum be negative?
Yes. In one-dimensional problems, a negative sign indicates motion in the opposite direction from the chosen positive direction.
What is relativistic momentum?
At speeds approaching the speed of light, the classical formula p = m·v is no longer accurate. Relativistic momentum is given by p = γ·m·v, where γ is the Lorentz factor.
Is 1 N·s the same as 1 kg·m/s?
Yes. Newton-second (N·s) and kilogram-meter per second (kg·m/s) are equivalent units of momentum and impulse.
How do I calculate mass from momentum and velocity?
Rearrange the momentum formula: m = p / v. Divide the momentum by the velocity.
How do I calculate velocity from momentum and mass?
Rearrange the momentum formula: v = p / m. Divide the momentum by the mass.
What is a perfectly inelastic collision?
In a perfectly inelastic collision, the two objects stick together after colliding. The final velocity is found using vf = (m₁v₁ + m₂v₂) / (m₁ + m₂).
Is this calculator free?
Yes, this calculator is completely free to use. No registration or personal data storage is required. All calculations are performed in your browser.