1. demos Intro: electricity is gonna be big

2. Ac/Hon Physics Notes Chapter 20 Electostatics

3. Lesson 1 Definitions and concepts

4. Objectives At the end of this lesson you will be able to: – Define electric charge and explain how forces act between charged objects

5. Electricity! Electricity: – Flow of electrons Electrostatics – Study of electrons (and protons) standing still

6. The Atom and Electric Charges Electrons – Negative charge Protons – Positive charge

7. Electrostatic Force Like charges repel each other Unlike charges attract each other The attraction or repulsion is called: – Electrostatic Force It is a force like all other forces we’ve studied in this class – Units = ?? – Newtons

8. Electrostatic Force vs. Gravity Electrostatic ForceGravitational Force Field force Force due to electric chargeForce due to mass Can repel or attractCan only attract

9. Other fun facts All Electrons and protons are the same regardless of what kind of atom

10. Questions What is electric charge? What causes electrostatic force? Why do like charges repel and vice versa? – Electrostatic Force Stop asking so many questions. We have no idea. Just accept it

11. How do we measure electric charge? Coulombs (C) – Charles-Augustin de Coulomb (1736-1806) Charge of an electron or proton e = 1.602 × 10 -19 C + for proton -for electron How do we get more charge (more Coulombs)? Add more electrons or protons Wait – do we ever add protons? We’ll get to this later….

12. What is the electrical charge of an atom? Zero It has the same # of protons and electrons Zero charge  Charge Neutral

13. How do we give something a charge? Add or take away electrons – Protons don’t move Adding electrons – Gives negative charge Removing electrons – Gives positive charge Atoms with a missing OR extra electron are called: – Ions

15. Conductors and Insulators Conductors – Electrons move easily through Insulators – Electrons stay put

16. Charge Conservation Electrical charge can never be created or destroyed It only moves

17. Lesson 2 Charging objects

18. Objectives At the end of this lesson you will be able to: – Solve problems involving moving of charge

19. Lesson 2 Charging objects

20. Objectives At the end of this lesson you will be able to: – Solve problems involving moving of charge

21. Ways things get charged Conduction – 2 things touch and electrons move Induction – 2 things come close to each other and electrons get pushed or pulled – we’ll explain this more soon…

22. What electrons like to do If there is no force on them, electrons spread out evenly

23. What’s up with “Ground” Earth is big It has a lot of electrons – really a lot If a charged object comes in contact with the earth, it automatically becomes neutral We say this object has been “grounded” Explain why…

24. Charging Problems Do on board – A charged object comes in contact with a charge neutral object (pos and neg) – A charged object come near a charge neutral object that’s grounded and the ground is removed.

25. Why will a charged object attract a charge neutral object like in the paper and ruler demo Do on board

26. Electorsopes A tool that tells you when it is charged. Do on board

27. Lesson 3 Coulomb’s Law

28. Objectives At the end of this lesson you will be able to: – Apply Coulomb’s Law

29. Coulomb’s Law