Answer:
0.86 m
Step-by-step explanation:
q₁ = magnitude of positive charge = 5 x 10⁻⁶ C
q₂ = magnitude of negative charge = 3 x 10⁻⁶ C
r = distance between the two charges = 0.250 m
d = distance of the location of third charge from negative charge
q = magnitude of charge on third charge
Using equilibrium of electric force on third charge
![(kq_(2)q)/(d^(2)) = (kq_(1)q)/((r+d)^(2))](https://img.qammunity.org/2020/formulas/physics/high-school/to1yfqzrtk9lfwrgbqajgankw3fyibp934.png)
![(q_(2))/(d^(2)) = (q_(1))/((r+d)^(2))](https://img.qammunity.org/2020/formulas/physics/high-school/m4djmwufwipppvmxqpunisj54kgqkcrnga.png)
![((5* 10^(-6)))/((0.250+d)^(2)) = ((3* 10^(-6)))/((d^(2))](https://img.qammunity.org/2020/formulas/physics/high-school/xtgpprgmqp4mpuj4cbou366k0bgaa088lc.png)
d = 0.86 m