4. Three point charges are located along the x-axis. Point charge q, = +3.5 x 10 *c is at x = 0, point charge q2 = +8.5 x 10 *c is at x = 2m, and point q; = -5.0 x 10 6c is at x = 3.0 m. Find the resultant force acting on q1. 5. Calculate the magnitude and direction of the electric field 0.45 m from a +7.85 x 10-9 point charge