Question

A +10.31 nC charge is located at (0,8.47) cm and a -2.09 nC charge is located (3.91, 0) cm. Where would a -14.84 nC charge need to be located in order that the electric field at the origin be zero? Express your answer, in cm, as the magnitude of the distance of q3 from the origin.

Answer 1

To make the E-field at the origin become 0, we need to find the E-field at the origin before

E = kq/r^2

E1 = 12934 V/m

E2 = 12303.69 V/m

Etotal = 17851.34 V/m

17851.34 = kq/r^2

r = 8.6526 cm