Just as for a charge moving in a uniform electric field, we can use our knowledge of gravitation to find an expression for the electric potential energy of two point charges \(q_1\) and \(q_2\) separated by a distance \(r\). In Section 10-2 we saw the following expression for the attractive gravitational force between two objects with masses \(m_1\) and \(m_2\) separated by a distance \(r\):