1. Electrostatics Electrostatics deals with electric charges at rest, or static electricity.

2. Electrical Forces and Charges  Electrical Charge – a force that one charge exerts on another  Charge – attracting or repelling between electrons and protons

3. Charge  Two types of charges:  Positive  Negative  Like charges repel and opposite charges attract.  positive charge - having more protons than electrons  negative charge - having more electrons than protons

4. Neutral  Electrically Neutral  an object has No Net Charge.  there are an equal number of protons and electrons.

5. Conductors and Insulators  conductors allow electric charge to travel through it easily  an insulator does not.  Materials are put into categories, depending on how easy charge (i.e., electrons) flows along them.  conductors - metals  semi-conductors - silicon  insulators - rubber, wood, plastic

6. The Law of Conservation of Charge  Conservation of Charge  The same number of electrons that leaves one object enters the other object  Electrons are not created or destroyed, they are transferred from one material to another

7. Methods of Charging  Conduction – charging a neutral object by contact with a charged object  Friction  Contact

8. Charging by Conduction  An object that is charged by contact has the same charge as the charging object.

9. Methods of Charging  Induction – charging an object with no direct contact (close but not touching)  Polarization - the process of separating opposite charges within an object, occurs in insulators

10. Charging by Induction  An object that is charged by induction has the opposite charge of the charging object.

11. Charging by Induction: Charged object drives off like charges, leaves charged object with opposite charge

12. Charging by Polarization  A charged object pushes like charges of a neutral object’s atoms away from one surface of an object – concentrates on opposite side.  Or attracts unlike charges to it

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15. Electric Field Lines

16. Field Lines  Number of lines per area represents field strength  As lines diverge, field strength diminishes  Lines emerge from positive charges and are directed inward toward negative charges

17. Positive Field Negative Field

18. Like Charges  Field lines do not cross  Repulsion

19. 2 Equal Positive Charges

20. Unequal Charges  Given a pos. charge that is 2X that of negative  Only half the lines that emanate will terminate in neg. charge

21. Rest of lines terminate at infinity Unequal Charges