- #1

- 327

- 1

## Homework Statement

Three point charges are arranged on a line. Charge q3 = +5.00nC and is at the origin. Charge q2 = -4.00nC and is at x = 4.50cm . Charge q1 is at x = 2.00cm.

What is q1 (magnitude and sign) if the net force on q3 is zero?

## Homework Equations

## The Attempt at a Solution

So first thing I did was draw a diagram where q3 was located at (0,0) q1 at (2.00cm,0) and q2 was located at (4.50cm,0)

Then after looking at the problem for a while I know I must use coulomb's law however since the net for q3 is 0 that threw me off a bit.

So what I decided to do was make two separate coulomb's law equations and equal them to each other.

(q1)^2/r^2=(q2)^2/r^2

Ultimately solving for q1 gives.

q1= √[(q2)^2*(r1^2)/r2^2]

Not sure if I'm on the right track just brainstorming, much help is appreciated

Higgenz