Frequently, more than two charges are present, and it is necessary to find the net electric force on one of them. Coulomb's law gives the electric force between any pair of charges. Coulomb's law also applies when more than two charges are present. Thus, the resultant force on any single charge equals the vector sum of the individual forces exerted on that charge by all of the other individual charges that are present. This is an example of the principle of superposition. Once the magnitudes of the individual electric forces are found, the vectors are added together. 1. Two point charges, each with a charge of +1.00 Coulomb are separated by a distance of 1.00 meter. Determine the magnitude of the electrical force of repulsion between them.

2. Two charges +25 C and +35 C are placed 10 m apart. What is the electric force acting on a third charge equal to -45 C place in midpoint between the two?

3. Draw a free body diagram to show the net electric force on the ball charge in the presence of the two charged rods?