A particle of charge -q1 is at the origin of an x axis. (a) At what location on the axis should a particle of charge -36q1 be placed so that the net electric field is zero at x = 2.8 mm on the axis? (b) If, instead, a particle of charge +36q1 is placed at that location, what is the direction (relative to the positive direction of the x axis) of the net electric field at x = 2.8 mm?

A particle of charge -q1 is at the origin of an x axis. (a) At what location on the axis should a particle of charge -36q1 be placed so that the net electric field is zero at x = 2.8 mm on the axis? (b) If, instead, a particle of charge +36q1 is placed at that location, what is the direction (relative to the positive direction of the x axis) of the net electric field at x = 2.8 mm?