26. (a) What is the direction of the total Coulomb force on q in Figure if q is negative, qa=qc and both are negative, and qb=qc and both are positive? (b) What is the dir...26. (a) What is the direction of the total Coulomb force on q in Figure if q is negative, qa=qc and both are negative, and qb=qc and both are positive? (b) What is the direction of the electric field at the center of the square in this situation? 82. (a) What is the electric field 5.00 m from the center of the terminal of a Van de Graaff with a 3.00 mC charge, noting that the field is equivalent to that of a point charge at the center of the terminal?