As noted before, the electrostatic force depends on the opposing electric charges and the distance that separates them.
The value of this electrostatic force is given by Coulomb's Law.
Where:
- F = electrostatic force that acts on each charge Q1 and Q2.
- K = a constant which depends on the unit system and the environment in which the charges are.
- r = distance between charges.
In the MKS system and in the vacuum:
Where
Then
With this value of k, the charges will be expressed in coulombs and the distance (R) in meters, in order to obtain a resultant force in Newtons.
- If the charges are of opposite signs (+ and -), F will be negative, which indicates attraction.
- If the charges are of the same sign (+ and + or - and -), F will be positive, which indicates repulsion.
Note: MKS System units: (Meters, Kilograms, Seconds)
