A small particle with mass \(m\) and positive charge \(q\) is projected from a very large distance directly toward a fixed, stationary point charge also with positive charge \(q\). The initial speed of the moving particle when far away from the fixed charge is \(v_0\). Electrostatic forces dominate all other interactions in this system. Which of the following expressions correctly represents the distance of closest approach \(r_{\text{min}}\) between the two charges?