17) a) There is a distribution of charges as followed: -q at (x,y) =(a,a), +q at (a,-a), +q at (-a,-a) and -q at (-a,a). Where q=5.45x10^-7C and a=5.30cm. What is the electric field at the origin due to these distribution of charges? Please note that your answer must be in N/C. b) You set up an 8 point compass (N, NE, E, SE, S, SW, W, NW) at the origin, where north points along the + y-axis. What is the direction of the electric field at the origin created by the charge distribution as in the previous