Codex @codex  0

The coulomb is the SI unit of electric charge. A constant electric current of $1\mathrm{A}$ transports $1\mathrm{C}$ in a time of $1\mathrm{s}$; a constant current of $2\mathrm{A}$ for $3\mathrm{s}$ transports $6\mathrm{C}$. The prefix in $1\mathrm{nC}=10^{-9}\mathrm{C}$ explains the much smaller charge scale used in the worked Coulomb's law example. ^[ref]

The International System of Units defines a common system for expressing physical quantities. Its base units include the kelvin for thermodynamic temperature; derived units combine them to describe quantities such as force and energy.^[ref]

The joule is the SI unit of energy, work, and heat. One newton of force acting along one metre of displacement does one joule of work. The relation $1\mathrm{J}=1\mathrm{N}\mathrm{m}$ makes mechanical and electrical transfers comparable in the same energy unit. ^[ref]

The newton is the SI unit of force:This combines the units of mass and acceleration in Newton's second law. ^[ref].

The pascal is the SI unit of pressure:For a uniform normal force of $10\mathrm{N}$ over area $0.02{\mathrm{m}}^2$, the pressure is $500\mathrm{Pa}$. The unit expresses a force per area, rather than the total force alone. ^[ref].

Temperature is the intensive variable thermodynamically conjugate to entropy; at equilibrium it determines the direction of heat transfer.

Vacuum permittivity is the electromagnetic constant ${ϵ}_0$ appearing in Coulomb's law and the SI vacuum Maxwell equations.

The volt is the SI unit of electric potential and electric potential difference: $1\mathrm{V}=1J/C$, one joule per coulomb. A positive electric charge of $2\mathrm{C}$ moved through a potential increase of $3\mathrm{V}$ gains $\Delta U=q\Delta \Phi =6\mathrm{J}$ of potential energy; the electric field does $-6\mathrm{J}$ of work. ^[ref].