2. Electrostatics the study of electrical charges at rest Electrodynamics the study of electrical charges in motion opposite Two opposite types of charge exist, named positivenegativeBenjamin Franklin in 1750 positive and negative by Benjamin Franklin in 1750.Benjamin Franklin Benjamin Franklin Charge is a property of matter.

3. Charged particles exist in atoms. Electrons are responsible for negative charge; protons for positive charge; neutrons have no charge. Small amounts of ordinary matter contain incredible amounts of subatomic particles!

4. Conductor material that allows charges to move about easily Insulator material through which charges will not easily move Basic Law of Electrostatics opposite charges attract; Like charges repel Link link

5. Click here to view ahere simulation of the behavior of pith balls in the vicinity of charged rods.

6. Click here to read about charging objects by friction. here View a simulation of charging a balloon by rubbing it on your hair and then sticking it to a neutral wall here. here

7. rodelectroscope charging a rod and electroscope positivelynegatively positively and negatively conduction induction by conduction and induction conduction When charging by conduction, touches the rod touches the electroscope. same charge The electroscope gets the same charge as the rod. induction does not When charging by induction, the rod does not touch touch the electroscope. The electroscope gets opposite charge the opposite charge of the rod.

8. Go here to view simulations of charging here an electroscope.

9. COULOMB’S LAW The force between two charged objects is directly proportional to the product of their charges and inversely proportional to their separation distance squared. link1

10. In equation form: F  F is the force of attraction, measured in newtons, between charges q 1 and q 2 k k is the Universal Electrostatic Constant, equal to 9.00 x 10 9 N m 2 /C 2 q1q1 q2q2 q 1 and q 2 are the attracting charges, measured in coulombs d2d2 d is the distance between the charges, and is measured in meters

11. The SI unit of charge is the coulomb, named in honor of Charles Augustin Coulomb Charles Augustin Coulomb. Charles Augustin Coulomb 1 C = charge on 6.25 x 10 18 electrons (or protons) 1 e - = 1.60 x 10  19 C = elementary charge Electric force is a vector and must be treated as such.

12. Example Problem What is the force on a +2.3 μC charge that lies 3.7 m to the left of a -5.1 μC charge? Given q 1 = +2.3 μC = +2.3 x 10 -6 Cd = 3.7 m q 2 = -5.1 μC = -5.1 x 10 -6 C k = 9 x10 9 N*m 2 /C 2 F = ? B.E. F = kq 1 q 2 /d 2 W.E. F = (9 x10 9 N*m 2 /C 2 )*(+2.3 x 10 -6 C)*(-5.1 x 10 -6 C) (3.7 m) 2 Answer F = -0.0077 N (“-” means attraction)

13. Example Problem How far is a +4.5 mC from a -8.2 mC if there is a force of 13 N between them? Given q 1 = +4.5 mC = +4.5 x 10 -3 Cd = ? q 2 = -8.2 mC = -8.2 x 10 -3 C k = 9 x10 9 N*m 2 /C 2 F = 13 N B.E. F = kq 1 q 2 /d 2 W.E. 13 N = (9 x10 9 N*m 2 /C 2 )*(+4.5 x 10 -3 C)*(-8.2 x 10 -3 C) d 2 Multiply both sides by d 2, then divide both sides by 13 N, then take the square root Answer d = 160 m