1. The problem statement, all variables and given/known data What are the magnitude and direction (in degrees counterclockwise from the horizontal) of the electric field at the center of the square of Fig. 23-31 if q = 0.9*10^-8 C and a = 5.1 cm? http://personalpages.tds.net/~locowise/23-30.gif 2. Relevant equations E=kq/r^2 k=8.99*10^9 N*m^2/C^2 3. The attempt at a solution Calculated r using the pythagorean theorem: 5.1cm--->.051m sqrt(.051^2+.051^2)=.07212m ...this is the length of the entire diagonal so r would be the diagonal divided by 2 which equals .036062445841 meters. Starting with E1 (the upper left hand corner of the square) and moving clockwise to E4... E1=+62214.53 N/C E2=-124429.07 N/C E3=+124429.07 N/C E4=-62214.53 N/C Here is where I get confused...do I resolve these in horizontal and vertical components? And, how do I find the angle? Thanks for your help!