Answer :
When you talk about "the strength of an electric force" in middle school, I'm pretty sure you're talking about the force between two electrostatic charges that either pulls them together or pushes them apart.
The strength of that force depends on
-- the product of the amounts of charges on the two charged objects
-- the distance between the centers of their charges.
The strength of that force depends on
-- the product of the amounts of charges on the two charged objects
-- the distance between the centers of their charges.
