Coulomb's Law

Like charges repel, unlike charges attract.

The electric force acting on a point charge q₁ as a result of the presence of a second point charge q₂ is given by Coulomb's Law:

where ε₀ = permittivity of space

Note that this satisfies Newton's third law because it implies that exactly the same magnitude of force acts on q₂ . Coulomb's law is a vector equation and includes the fact that the force acts along the line joining the charges. Like charges repel and unlike charges attract. Coulomb's law describes a force of infinite range which obeys the inverse square law, and is of the same form as the gravity force.

For q1 =  x10^ C q2 =  x 10^ C and r =  meters, F=  x 10^ Newtons.

A negative force implies an attractive force. The force is directed along the line joining the two charges.

Electric force example

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