A change of -3.00 uC is fixed at the center of a compass. two additional charges are fixed on the circle of the compass, which has a radius of 0.100m. the charges on the circle are -4.00uC at the position due north and +3.00uC at the position due east. what are the magnitude and direction of the net electrostatic force acting on the charge at the center? specify the direction relative to due east.