9. Three charges with q = +7.5 × 10-6 C are located as shown in Figure 7, with L = 25 cm. Determine the magnitude and direction of the total electric force on each particle listed below.

(a) the charge at the bottom (b) the charge on the right (c)an electron placed at the origin . Two pith balls, each with a mass of 5.00 g, are attached to non-conducting threads and suspended from the same point on the ceiling. Each thread has a length of 1.00 m. The balls are then given an identical charge, which causes them to separate. At the point that the electric and gravitational forces balance, the threads are separated by an angle30.0°. Calculate the charge on each pith ball. K ASS