Question

4) A +7.00 μC point charge and -9.00 μC point charge are placed along the x-axis at x = 0.000 cm and x = 40.0 cm, respectively. Where must a third charge, q, be placed along the x-axis so that it does not experience any net electric force due to the other two charges?
A) -0.200 m
B) 2.99 m
C) -0.187 m
D) -2.99 m
E) 0.187 m