An attractive central force exerted on a particle of mass \(m\) causes the particle to travel in a bound orbit. The orbit is clliptical with semimajor axis \(a\), and the force has magnitude \(\mathrm{C} m / r^{2}\), where \(\mathrm{C}\) is a constant and \(r\) is the orbit radius. If the particle's speed is \(v=\sqrt{C / 2 a}\) when it is farthest from the source of the force, what is its speed when it is nearest the force source?