Question

A negative point charge q1 = 25 nC is located on the y axis at y = 0 and a positive point charge q2 = 10 nC is located at y =14 cm. Find the y coordinate of the points where the net electric potential due to these two charges is zero.

Answer 1

y = 0.1 m

Step-by-step explanation:

The electrical power for point loads is

V =
`k \sum (q_i)/(r_i)`k Sum qi / ri

in this case

V = k (
`- (q_1)/(r_1 ) + (q_2)/(r_2)`)

indicate that V = 0

`(q_1)/(r_1) = (q_2)/(r_2)`

r₂ =
`(q_2)/(q_1) r_1`

the distance r1 is

r₁ = y -0

the distance r2

r₂ = 0.14 -y

we substitute

0.14 - y =
`(10)/(25)` y

y (
`(10)/(25) + 1`) = 0.14

y 1.4 = 0.14

y = 0.14 / 1.4

y = 0.1 m