Five point charges are located on the y-axis. Two are positive with charge q = 0.37mC and three are negative with charge q = -0.37mC. The positive charges are a = 4.5m away from the origin. What is the net electric field at the origin due to these charges?
a) 0
b) -2.7 kN/C
c) -1.35 kN/C
d) -5.4 kN/C
