?

Electricity and Magnetism

Free Version

Upgrade subject to access all content

Moderate

Coulomb's Law for Charges in Row

EANDM-MJTFQV

Three positive charges $Q$, $q$, and $\cfrac{Q}{3}$ are placed in a straight line with $q$ in between the other two. The distance between $Q$ and $q$ is the distance $R$.

At what distance, $x$, on the other side of $q$ must the charge $\cfrac{Q}{3}$ be placed in order for the net Coulomb force on $q$ to be zero?

Created for Albert.io. Copyright 2016. All rights reserved.

A

$$ x = \cfrac {R}{\sqrt {3}}$$

B

$$ x = {R}{\sqrt {3}}$$

C

$$ x = \cfrac {R}{{3}}$$

D

$$ x = 3 R$$

E

$$ x = 9 R$$