Question

Part (a) of the figure below shows two charged particles fixed in place on an x axis with separation L. The ratio q1/q2 of their charge magnitudes is 36.0. Part (b) of the figure shows the x component Enet,x of their net electric field along the x axis just to the right of particle 2. The x axis scale is set by xs = 30.0 cm.
(a) At what value of x > 0 is Enet, x maximum? (The maximum is not at x = xs.)
cm

(b) If particle 2 has charge −q2 = −3e, what is the value of that maximum?