Determine components and directions of the electric force and/or field. (cont.) The electric force acting on q, acts to the left, in the direction away from 92. The unknown quantities to be determined in part (b) are the magnitude and direction of the electric field at x = 0. To solve part (b), we return to the application of Coulomb's law and the electric field expression in the Problem Solving Strategy. Apply Coulomb's law and the electric field expression, as required. The electric field magnitude at some distance r from a point charge q is lql E == ke 7 where k = 8.99 x 109 Nm/C. The electric field is directed radially outward from a positive charge and radially inward toward a negative charge. In this situation, both charges q, and q2 will contribute to the net electric field at x = 0 so that E = E + E, where the subscript of 1 or 2 indicates the electric field (magnitude and direction) at x = 0 due to charge q or q2, respectively. In general, E + E + E, because the electric field has b.