The calculation, without hidden assumptions
Linear momentum is p = mv. OpenStax emphasizes that momentum is a vector with the same direction as velocity, so a signed one-dimensional velocity produces signed momentum. MAXScanner keeps that sign, solves any of p, m or v, and reports the exact impulse-equivalent unit N·s plus kinetic-energy context for the same mass and speed.
How to use this calculator
Choose momentum, mass or velocity as the unknown.
Enter the two known quantities and their units; velocity/momentum may be signed to represent one-dimensional direction.
Inspect the SI-normalized multiplication or division and converted output.
Use the impulse-equivalent and kinetic-energy diagnostic to distinguish momentum from energy.
Where people use it
- •Classical mechanics checks involving mass and signed velocity
- •Reverse-solving velocity for a specified momentum and known mass
- •Comparing impulse/change-in-momentum units with a current momentum value
- •Keeping momentum and kinetic energy separate when analyzing moving objects
Worked example — 5 kg at −12 m/s
p = 5 × (−12) = −60 kg·m/s = −60 N·s. The negative sign indicates the chosen negative direction; it does not mean the object has negative mass.
What the result does not assume
- •Momentum is a vector. This scalar-input calculator represents direction with a plus/minus sign along one chosen axis; full 2D/3D momentum requires vector components.
- •A momentum value alone is not a collision outcome. Conservation analysis requires the complete system and external-force boundary.
- •For relativistic speeds, classical p = mv is not the relativistic momentum expression.
Frequently asked questions
Can momentum be negative?+
Yes. In a one-dimensional signed coordinate system, negative momentum means velocity points in the chosen negative direction.
Is momentum the same as impulse?+
They have the same SI unit, and impulse equals change in momentum Δp. A current momentum value is not itself a time-integrated force event.
Can this solve mass or velocity?+
Yes. It uses m = p/v or v = p/m, rejecting states that would require division by zero or a negative mass.
Why show kinetic energy too?+
Momentum and kinetic energy describe different properties of motion. Showing K = ½mv² for the same state helps prevent treating kg·m/s and joules as interchangeable quantities.
Semantic next steps
Continue the calculation
These links move to a different input, formula or project stage rather than a keyword variation of this page.
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