Chapter 4: Q62P (page 717)
Two identical spheres with mass m are hung from silk threads of length L (Fig. P21.62). The spheres have the same charge, so q1 = q2 = q. The radius of each sphere is very small compared to the distance between the spheres, so they may be treated as point charges. Show that if the angle u is small, the equilibrium separation d between the spheres is d = (q2尝/2饾洃蔚0尘驳)1/3 (Hint: If饾泬is small, then tan饾泬鈮卻in饾泬.)

Short Answer
If the angle u is small, the equilibrium separation d between the spheres is .
