Hi guys, here's a question i thought i knew how to solve but somehow it doesn't work. been trying and trying for almost a week :-( here it is: "A thin wire is bent in the form of a rectangle with length l = 12 cm and width w = 10 cm. The wire is charged up to a uniform charge density of 5.5×10-6 C/m. Find the magnitude of the electric field at a distance of 65 cm from the center of the rectangle along the axis." http://img73.imageshack.us/img73/2673/11542as4.gif [Broken] I've tried calculating the sum integral of the field at that point using gauss' law for each side of the frame but i don't get it right. I know how to integrate, so i don't think it's a calculation error, maybe my integral is wrong. or maybe there's a better way? Thanks!