1. The problem statement, all variables and given/known data The conducting box has been given an excess negative charge. The surface density of excess electrons at the center of the top surface is 31 x 10^10 electrons/m^2. What is the electric field strength at point 1? http://img401.imageshack.us/img401/680/knightfigure27262bn2.jpg [Broken] 2. Relevant equations E = linear charge density/E0 linear charge density=q/L q=N(e) 3. The attempt at a solution First I found the charge q=Ne =(31*10^10 electrons/m^2)*(1.6*10^-19) =5*10^-8 C/m^2 E=(5*10^-8 electrons/m^2)/(8.85*10^-12) =5604.5 Can someone please conform if am right ?