1. Electrostatics – Coulomb’s Law

2. Coulomb’s Law + + + + + + + + + + + + + + + + + + __ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ Charles Coulomb discovered that the repulsive force due to similar charges or the attractive force of dissimilar charges was inversely proportional to the square of the distance between the two charged bodies. r F  1/r 2

3. Coulomb’s Law Coulomb further discovered that the force was proportional to the product of the charge on each of the objects. + + + + + + + + + + + + + + + + + + __ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ F  q 1 q 2 q2q2 q1q1 Sphere 1Sphere 2

4. Coulomb’s Law Where: k = 8.99 x 10 9 Nm 2 /C 2 q 1, q 2 = the charge of each sphere in Coulombs. r = the distance between the two charged bodies. Applet 1 - Coulomb's Law Applet II - Coulomb's Law Does this formula appear similar to anything else you have seen before?

5. Key Ideas Like charges repel. Opposite charges attract. The electrostatic force is proportional to the charge on the two objects and inversely proportional to the square of the distance between them.