[[Electrodynamics MOC]]
# Poynting vector

The **Poynting vector** is a vector quantity representing a flow of electromagnetic energy at a point,
defined by
$$
\begin{align*}
\vab S = \frac{1}{\mu_{0}} \vab E \times \vab B
\end{align*}
$$
To see how this represents energy flow, see [[Poynting's theorem]].
The Poynting vector is related to [[Electromagnetic momentum density]] by
$$
\begin{align*}
\vab g = \epsilon_{0}\mu_{0} \vab S
\end{align*}
$$


#
---
#state/tidy | #lang/en | #SemBr