Physics
Momentum from mass and speed
The linear companion to kinetic energy. Momentum grows in proportion to speed rather than its square, and it is a vector.
The Formula
p = m v
The linear companion to kinetic energy. Momentum grows in proportion to speed rather than its square, and it is a vector.
| Symbol | Meaning | Unit | Notes |
|---|---|---|---|
| m | Mass of the object | kilograms | The same mass used for the energy calculation. |
| v | Speed of the object | metres per second | In metres per second, matching the energy calculation exactly. |
| p | Momentum | kilogram metres per second | A vector pointing along the direction of motion, so signs matter. |
What Each Symbol Means
mkilograms
Mass of the object
The same mass used for the energy calculation.
vmetres per second
Speed of the object
In metres per second, matching the energy calculation exactly.
pkilogram metres per second
Momentum
A vector pointing along the direction of motion, so signs matter.
See It Worked With Real Numbers
A formula on its own does not tell you which number goes where. The how to calculate kinetic energy page applies this equation to a concrete case, shows every intermediate step, and names the mistakes that produce a wrong answer even when the algebra is right.
Where This Formula Appears
This equation is the working core of How To Calculate Kinetic Energy, filed under Science. Every number the guide produces comes from substituting into this one line.