The interaction between electrically charged objects is a phenomenon that is revealed even when the objects are not in direct contact, as the electromagnetic interaction acts at a distance.

Furthermore, this interaction can be attraction or repulsion depending on the charge of each object, three variables come into play:

loading of the first object loading of the second object distance between themCoulomb’s law, also known as Coulomb’s Law, is a physical law that relates these three variables and quantifies the force of repulsion or attraction between two electrically charged objects. In its scalar form, this is Coulomb’s Law Formula:

where k is the Coulomb constant (*k* ≈ 9×109 Nmtwo C−2), *which*1 and *which*two is the magnitude of the charge on each object and rtwo is the square of the distance between them.

From the formula it follows that the interaction force is attractive if the charges have opposite signs which results in negative F and is repulsive if the two charges have the same sign which results in positive F.

That is, given two 1st quarter point charges S q2 separated a distance r in vacuum, they attract or repel each other with a force whose magnitude is given by Coulomb’s formula.

It is worth noting that Coulomb’s Law formula has the same form as Newton’s Law of Universal Gravitation:

## Force as vector magnitude

In physics, magnitudes can be vector or scalar, depending on whether the measured property is associated, in addition to a numerical value, with a direction and a spatial orientation. Electric force, like any other force, is a vector magnitude since it is exerted in a specific direction and direction.

So, according to Coulomb’s Law, the force between two electric charges is:

directly proportional to the magnitude of the charges (q1, q2) inversely proportional to the square of the distance between them (rtwo) manifests in the direction of the vector connecting the center of each charge (r̂) the direction of the force is attractive if the charges are of the same sign (both are positive or both are negative) the direction of the force is repulsive if the charges are of opposite sign (one positive and one negative)