Online calculator: Coulomb's law

The calculator below is about Coulomb's law. It allows you to calculate unknown value (whether force, charge or distance) using known values and scalar formula

The scalar form of theCoulomb's law equation is:
$|\mathbf F|=k_e{|q_1q_2|\over r^2}\qquad$
where k is Coulomb's constant
$k=\frac{1}{4\pi\varepsilon_0}$
with epsilon (electrical constant) is ≈ $8.85418781762*10^{-12} F/m$

This calculator can be useful in solving school physics problems.
Typical problems could look like these:

Suppose that two point charges, each with a charge of +1.00 Coulomb are separated by a distance of 1.00 meter. Determine the magnitude of the electrical force of repulsion between them
Two balloons with charges of +3.37 µC and -8.21 µC attract each other with a force of 0.0626 Newton. Determine the separation distance between the two balloons.

Thus, first you choose the value you want to get, then you fill known values and receive answer.