located at a point with position vector 
where the electric field is 
the electrostatic force is
is: the force that acts on a charged body due to its location in a static electric field. For a test charge located at a point with position vector where the electric field is the electrostatic force is
[P3.3]
is exemplified: by the force (described by Coulomb's law) that one charged particle exerts on another by virtue of the electric field that it creates. Two particles with charge of the same sign repel one another, and two particles with charge of the opposite sign attract one another. [P3.1]
is given: for a positive unit charge by the negative derivative of electric potential energy in the direction of maximum change (e.g. in the radial direction from an isolated point charge, 
). [P3.1, P3.3]
Copyright 1997, The Open University