\section{Electric Potential and Energy}

This unit develops the energy viewpoint for electrostatics. In AP Physics C: Electricity and Magnetism, the central idea is that electric interactions can be described not only with the vector field $\vec{E}$ but also with the scalar quantities electric potential energy $U$ and electric potential $V$. That scalar viewpoint often makes multi-charge systems and energy changes easier to analyze.

The flow begins with electric potential energy for charge configurations, then defines electric potential and voltage, connects potential to the electric field, and finishes with equipotentials and the energy changes of moving charges. The scope here is electrostatics only, so the field remains conservative and no induction-related electric fields are considered yet.

\input{concepts/em/u9/e9-1-electric-potential-energy.tex}

\input{concepts/em/u9/e9-2-potential-voltage.tex}

\input{concepts/em/u9/e9-3-field-potential.tex}

\input{concepts/em/u9/e9-4-equipotentials.tex}