Momentum Calculator - p = mv
Calculate momentum from mass and velocity, or solve for mass or velocity given the other two variables.
Result
20.0000
p = m × v = 5 × 4 = 20.0000 kg·m/s
How to Calculate Momentum
Momentum is the product of an object's mass and its velocity. This calculator solves for any one of the three variables — momentum, mass, or velocity — given the other two, using standard SI units of kilograms, meters per second, and kilogram-meters per second.
Example
A 5 kg object moving at 4 m/s has a momentum of p = 5 × 4 = 20 kg·m/s. If you instead knew the momentum (20 kg·m/s) and the mass (5 kg), you could solve for velocity: v = 20 / 5 = 4 m/s.
Common Use Cases
- Physics homework involving linear momentum and collisions.
- Comparing the momentum of objects with different masses and speeds.
- Setting up conservation-of-momentum problems for a collision or explosion scenario.
FAQs
What units does this calculator use?
Standard SI units: mass in kilograms (kg), velocity in meters per second (m/s), and momentum in kilogram-meters per second (kg·m/s).
Is momentum the same as kinetic energy?
No — momentum (p = m × v) scales linearly with velocity, while kinetic energy (KE = 0.5 × m × v²) scales with velocity squared. Two objects can have the same momentum but different kinetic energy, or vice versa, if their masses and speeds differ in the right way.
Can momentum be negative?
Yes — momentum is a vector quantity, so its sign reflects direction. A negative velocity (moving in the opposite direction of your chosen positive direction) produces a negative momentum value, which matters when adding up momentum across multiple objects.