posted by JOTHEY .
A -3.0 nC charge is on the x-axis at x = -10 cm and a +4.0 nC charge is on the x-axis at x = 20 cm.
At what point or points on the y-axis is the electric potential zero?
electric potential is the scalar addition of each component.
V= kq/r+ kq/r= -k3.0nC/(r+0.10)+k4nC/(r-0.20)
r= -.6-.4= -1meter