Charges

Electricity and Magnetism Level 2

What is the force between two charged particles of 20 Coulombs and 15 coulombs 2 metres apart?

Note: Coulombs constant is equal to 9e+9

2.43e+10 N 7.34e+9 N 1.64e-8 N 6.75e+11 N

1 solution

A Former Brilliant Member
Oct 18, 2017

We can use the formula

$F=k\dfrac{Q_AQ_B}{r^2}$ where $Q_A$ and $Q_B$ are the charges, $r$ is the distance between them, and $k$ is the Coulombs constant.

So,

$F=(9 \times 10^9)\left[\dfrac{20(15)}{2^2}\right]=6.75 \times 10^{11}~N$