Conservation of Linear Momentum
The law stating that total linear momentum of an isolated system remains constant if no net external force acts on it.
Governing formula
∑ p_initial = ∑ p_final
SI unit
kg·m/s
In depth
Fundamental consequence of spatial translation invariance (Noether's theorem). Holds in both elastic and inelastic collisions.
Examples in the real world
Recoil velocity of a rifle when firing a bullet, or billiard ball collisions.