COULOMB’S LAW
The electric force between two charged particles obeys the same mathematical law
as the gravitational force between two masses—that is, it’s an inverse-square law.
The electric force between two particles with charges of q 1 and q 2 , separated by a
distance r, is given by the equation
It’s Electric!
An electrical force is much
stronger than gravitation
force: It’s what keeps
matter together. If you
were to compare the
electric force between an
electron and proton (using
their charges) to the gravitational
force (using their
masses), the electric force
would be about 135,000
times stronger.This is Coulomb’s law.The absolute value symbol is needed to give the magnitude of the force. Some
books omit the absolute value symbol around the charges and state that a negative
force indicates attraction while a positive force indicates repulsion. This, however,
can lead to confusion. Remember that each charge feels this force, equal in
magnitude and indirection (Newton’s third law).