Momentum Calculator

Calculate signed linear momentum from positive mass in kilograms and velocity in metres per second.

Calculate linear momentum

Momentum: 48 kg·m/sA negative velocity produces momentum in the opposite selected direction.

How this tool works

Linear momentum combines an object's mass with its velocity and retains direction through the velocity sign. Unlike kinetic energy, momentum changes sign when motion reverses, which matters in collision and conservation analysis.

Linear momentum p equals mass m multiplied by velocity v. SI units are kilogram-metres per second, and the sign follows the selected velocity direction.

How to use it

  1. Enter positive mass in kilograms.
  2. Enter signed velocity in metres per second.
  3. Read momentum with its directional sign.

Worked examples

Forward motion

Input
8 kg at 6 m/s
Output
48 kg·m/s

Momentum is directly proportional to both quantities, so multiplying eight kilograms by six metres per second gives forty-eight.

Reverse direction

Input
3 kg at -4 m/s
Output
-12 kg·m/s

Negative velocity represents motion opposite the chosen positive axis, producing momentum with the same negative direction sign.

Limitations

  • The tool handles one-dimensional scalar components rather than full vectors.
  • Relativistic momentum requires a different formula at extreme speeds.