The moment is the product of distance and a physical quantity, such as Charge, magnetism, or even Force. It has different orders, which represent how many of the specific quantities exist.
Definition
Moment
\vec{\mu}{n} = \vec{r}^n \times \vec{Q} \iff \mu{n} = r^n Q \quad\quad (\vec{r} \perp \vec{Q})
>[!terms]- > >* $\mu$ = Moment (Units are determined by $Q$) >* $r$ = Distance from a given origin point. >* $Q$ = Physical quantity, for example can be [Charge](charge.md) ($q$), or force ($F$) >* $n$ = Order of moment > * $n = 0$ is the 0th moment (one object) > * $n = 1$ is the 1st moment, also called the **dipole moment** (two objects) > * $n = 2$ is the 2nd moment, also called the quadrupole moment
Examples
- Torque is the first moment of Force ()
- Angular Momentum is the first moment of linear momentum
- The electric dipole moment is the first moment of charge.