Chapter 21, Problem 61P

(II) A positive charge q is placed at the center of a circular ring of radius R. The ring carries a uniformly distributed negative charge of total magnitude −Q. (a) If the charge q is displaced from the center a small distance x as shown in Fig. 21–69, show that it will undergo simple harmonic motion when released. (b) If its mass is m, what is its period?

FIGURE 21–69

Problem 61.