Finding where Magnetic Fields = 0

[nmacholl]

Homework Statement

Two point charges, -520x10^-6C and -270x10^-6C are 2 meters apart. At which point would a carbon nucleus experience zero net force?
(positive test charge)

Homework Equations

k=9x10⁹
F=k((q₁*q₂)/r²) Coulomb's Law
E=k(q₁/r²)=(F/q₂)

The Attempt at a Solution

I really don't understand the method to solving the problem. A simply outline of what to find and then how to manipulate the equations to get the distance would really help me solve this. Fiddling has gotten me nowhere.

Thanks

 

[LowlyPion]

There are 2 forces acting on the test charge.

Where the forces are equal ...

If that point is X meters from one charge then it must be 2 - X from the other.

Just a little bit of algebra should give you what you need.

Btw: This has nothing to do with magnetism.