Question

There are two charged spheres that are 1 meter apart. The electrostatic force between them is 100 [N]. If you double the distance between the spheres to 2 meters, what will the new electrostatic force be?

Answer 1

The formula for the electrostatic force between two charges is given by:

$F=\frac{K\cdot q_1\cdot q_2}{d^2}$

Where F is the force (in N), K is the electrostatic constant, q1 and q2 are the charges (in C) and d is the distance between them (in m).

If the force is 100 N for a distance of 1 m, we have:

$\begin{gathered} 100=\frac{K\cdot q_1\cdot q_2}{1^2}\\ \\ Kq_1q_2=100 \end{gathered}$

Now, doubling the distance, we have:

$F_2=\frac{K\cdot q_1\cdot q_2}{2^2}=\frac{100}{4}=25\text{ N}$

Therefore the new electrostatic force is equal to 25 N.