Electric potential energy of two point charges (17-3)

Question 1 of 4

Question

Values of the two charges

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Review

This expression is very similar to Equation 10-4 for gravitational potential energy. Equation 17-3 shows that $U_{\mathrm{electric}}$ is inversely proportional to the distance $r$ , so the electric potential energy is zero when the two charges are infinitely far apart $r \to \infty$ ). But unlike gravitational potential energy, $U_{\mathrm{electric}}$ can be either negative or positive depending on the signs of the two charges. If $q_1$ and $q_2$ have different signs (one positive and one negative) so that the two charges attract each other, then $U_{\mathrm{electric}} < 0$ for any finite distance $r$ between the charges (Figure 17-4b).