Please help...!!! I tried!!! I even draw this picture. Please help! PICTURE CLICK HERE 1. The problem statement, all variables and given/known data Determine the electric field strength at a point 0.01m to the left of the middle charge. 2. Relevant equations Electric Field E = Ke (q / (r^2) ) Electric Force F = Ke (q1q2 / r^2) Constant Ke = 9.00e9 Nm^2/C^2 3. The attempt at a solution http://img504.imageshack.us/img504/5137/myillustrationql5.jpg [Broken] Let 7e-6C be q1, 1.0e-6 q2, and -3e-6C q3. So if you start at the middle charge and go 0.01m to the left, I imagine a point P, and the distance between the middle charge and point P should be 0.01m I think... So from there... E q1 on P = 9e9 Nm^2/C^2 ( 7e-6C / 0.03m^2 ) = 7e7 N / C. E q2 on P = 9e9 Nm^2/C^2 ( 1e-6C / 0.01m^2 ) = 9e7 N / C. E q3 on P = 9e9 Nm^2/C^2 ( -3e-6C / 0.03m^2 ) = -3e7 N / C. 0.03m because 0.01m+0.02m I think. Enet = 7e7 + 9e7 - 3e7 = 1.3e8 N/C. But that's wrong! Then you have to find the magnitude (in Newtons) if a charge of -3e-6C is placed at this imaginary point.