Difference between revisions of "Functions composed of Physical Expressions"

Revision as of 23:02, 14 May 2016

Functions for a point charge $q'$

The electric scalar potential $\mathbf{\varphi}$ at $\left(\mathbf{r},t\right)$ due to a point charge $q'$ at $\left(\mathbf{r'},t'\right)$ is:

$\mathbf{\varphi}\left(\mathbf{r},\mathbf{r'}\right) = \underset{constant}{\frac{q'}{4\pi\ \epsilon_0}} \times \underset{proximity}{\frac{1}{|\mathbf{r}-\mathbf{r'}|}}$

The magnetic vector potential $A$ at $\left(\mathbf{r},t\right)$ due to a point charge $q'$ which had a velocity $\frac{d\mathbf{r'}}{dt}$ at $\left(\mathbf{r'},t'\right)$ is:

$\mathbf{A}\left(\mathbf{r},\mathbf{r'}\right) = \mathbf{\varphi}\left(\mathbf{r},\mathbf{r'}\right) \times \underset{constant}{\frac{1}{c^2}} \times \underset{dislocation}{\frac{d\mathbf{r'}}{dt}}$

$\mathbf{A}\left(\mathbf{r},\mathbf{r'}\right) = \underset{constant}{\frac{\mu_0\ q'}{4\pi}} \times \underset{proximity}{\frac{1}{|\mathbf{r}-\mathbf{r'}|}} \times \underset{dislocation}{\frac{d\mathbf{r'}}{dt}}$

Functions for an ordered pair of point charges $(q,q')$

A charge $q$ subject to an electric scalar potential $\mathbf{\varphi}$ at $\left(\mathbf{r},t\right)$ due to a point charge $q'$ at $\left(\mathbf{r'},t'\right)$ has an electric potential energy of:

$q\mathbf{\varphi}\left(\mathbf{r},\mathbf{r'}\right) = \underset{constant}{\frac{qq'}{4\pi\ \epsilon_0}} \times \underset{proximity}{\frac{1}{|\mathbf{r}-\mathbf{r'}|}}$

A charge $q$ subject to a magnetic vector potential $A$ at $\left(\mathbf{r},t\right)$ due to a point charge $q'$ which had a velocity $\frac{d\mathbf{r'}}{dt}$ at $\left(\mathbf{r'},t'\right)$ has a potential momentum of:

$q\mathbf{A}\left(\mathbf{r},\mathbf{r'}\right) = \mathbf{\varphi}\left(\mathbf{r},\mathbf{r'}\right) \times \underset{constant}{\frac{1}{c^2}} \times \underset{dislocation}{\frac{d\mathbf{r'}}{dt}}$

$q\mathbf{A}\left(\mathbf{r},\mathbf{r'}\right) = \underset{constant}{\frac{\mu_0\ qq'}{4\pi}} \times \underset{proximity}{\frac{1}{|\mathbf{r}-\mathbf{r'}|}} \times \underset{dislocation}{\frac{d\mathbf{r'}}{dt}}$

See also

• The Anatomy of a Physical Expression

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