Question

Point charges create equipotential lines that are circular around the charge (in the plane of the paper). What is the potential energy, in nJ, of a 1 nC charge located 0.93 m from a 2 nC charge ?

Answer 1

The potential energy of a pair of point charges is given by:

`U=k(q_1q_2)/(r)`

In this case we have that the distance between the charges is 0.93 m and the charges are 1 nC and 2 nC; plugging these values we have:

`\begin{gathered} U=(9*10^9)((1*10^(-9))(2*10^(-9)))/((0.93)) \\ U=19.35*10^(-9) \end{gathered}`

Therefore, the potential energy is 19.35 nJ