Explain how the electric force between two positive charges changes under the following conditions:

1. the distance between the charges is tripled

2. the amount of one charge is doubled

1. the distance between the charges is tripled

using coulomb's formula;

F=k Q1Q2/r^2.

the force is inversely proportional to the square of the distance between them.

therefore when the distance is tripled the electric force decreases.

2. the amount of one charge is doubled

from the formula the force is directly proportional to the product of the charges. Therefore when the amount of one charge is increased the electric force between them increases as well.