• The electric potential a distance $r$ from a point charge $q$ is $V = \frac{kq}{r}$
• The total electric potential at a point P for a system of charges equals the algebraic sum of the potentials at P due to each individual charge at a distance that separates the charge and P

<aside> 🔌 For an electric potential from a point source charge $q_1$, the work done moving a test charge $q_2$ from an initial separation $r_i$ to a final separation $r_f$ equals the change in electric potential energy: $W = E_{Ef} - E_{Ei}$ $W = \frac{kq_1q_2}{r_f}-\frac{kq_1q_2}{r_i}$

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For a system of two charges $q_1$ and $q_2$, separated by a distance $r$, the electric potential energy is $E_E = \frac{kq_1q_2}{r}$

<aside> 🔌 The potential energy difference of two point charges, $q_1$ and $q_2$, as the separation between them changes from $r_i$ to $r_f$ is: $\triangle E_E = E_{Ef} - E_{Ei}$ $\triangle E_E = \frac{kq_1q_2}{r_f}-\frac{kq_1q_2}{r_i}$

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• When the amount of charge on the dome of a Van de Graaff generator is high enough, the electrons may jump from the sphere, producing artificial lighting