Linear Momentum (p)
The product of an object's mass and velocity. It is a vector quantity, meaning direction matters.
p = m · v
Momentum Calculator
Calculate linear momentum, mass, or velocity with unit conversion.
Momentum Calculator
Calculate Linear Momentum and Impulse (Change in Momentum) for physics and engineering.
Physics Formula
p = m · v
Momentum & Impulse Explained
Momentum describes the "oomph" of a moving object. Heavier and faster objects have more momentum. Impulse describes the effect of a force acting over time, which causes a change in momentum.
Impulse (J)
The integral of force over time. Impulse equals the change in momentum ($\Delta p$).
J = F · Δt = Δp
momentum formulas and interpretation
Linear momentum describes motion as the product of mass and velocity.
Momentum is a vector, so its sign or components represent direction.
How to use the momentum calculator
- Choose a model: Select the relationship matching the problem.
- Choose the unknown: Select the quantity to calculate.
- Enter values: Enter all known values with matching units and signs.
- Calculate: Review the result, formula, units, and direction.
Formula and variables
Linear momentum equals mass multiplied by velocity.
p = mv- p — Momentum
- Quantity of linear motion (kg·m/s)
- m — Mass
- Object mass (kg)
- v — Velocity
- Speed with direction (m/s)
Moving object example
A 4 kg object moves at 6 m/s.
- Mass
- 4 kg
- Velocity
- 6 m/s
- p = 4 × 6
- p = 24 kg·m/s
Result: Momentum is 24 kg·m/s.
The object carries 24 kg·m/s in its direction of travel.
Understanding your results
Interpreting the result
Momentum direction follows velocity when mass is positive.
Assumptions
- The selected equation represents the physical system.
- Inputs use a consistent reference direction.
- Values are converted through coherent SI units.
Limitations
- Vector components must be resolved along a common axis.
- External forces or energy losses are not added automatically.
- Results depend on the accuracy of entered measurements.
Common mistakes
- Mixing incompatible units.
- Dropping negative signs that represent direction.
- Using weight where mass is required.
- Entering a zero divisor.
Practical use cases
Physics problems
Check classroom, laboratory, and mechanics calculations.
Practical estimates
Estimate motion, forces, and energy for real systems.
Frequently asked questions
Can a result be negative?
Yes. For directional quantities, the sign indicates direction relative to the chosen positive axis.
Should I use SI units?
The interface can convert supported units, while the formulas are evaluated through coherent SI units.
Sources and review
- SI Brochure, 9th edition — BIPM. Accessed 2026-07-11.
- Special Publication 811 — NIST. Accessed 2026-07-11.
Reviewed 2026-07-11.
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