1. Electrostatics
Chapter 32

2. Electrostatics Electricity at rest Electricity = flow of electrons
Involves electric charges, forces between them and their behavior in materials
Electricity = flow of electrons

3. Electrical Forces & Charges
Charges can either be attracting or repelling
Caused by protons (positive charge) and electrons (negative charge)
Like charges repel; opposite charges attract

4. Conservation of Charge
Electrons are neither created nor destroyed but are simply transferred from one material to another
Charge is conserved

5. Coulomb’s Law for charged particles or objects
small compared with the distance between them,
force between the charges varies directly as the product of the charges and inversely as the square of the distance between them.

6. F = k q1q2 d2
F= force between charges
q1= quantity of charge of one particle
q2= quantity of charge of other particle
d= distance between charged particles
k= proportionality constant (9.0 x 109 Nm2/C2)

7. Unlike gravitational forces, electrical forces can attract or repel.
Electrical forces > gravitational forces

8. Conductors & Insulators
Materials whose outer electrons are free to roam (loosely bound)
Metals
Insulators
Electrons are tightly bound and remain with the atom (do not conduct electricity)
Rubber, wood, plastic

10. Charging by Friction & Contact
Electrons can be transferred from one material to another by touching (charging by contact)
Electrons can be transferred by friction when one object rubs against another

11. Charging by Induction
If a charged object is brought near a conducting surface, electrons will move even if there is no physical contact.

12. Charge Polarization
Occur when a charged object is brought near an insulator.
There is a rearrangement of the positions of charges within the atoms and molecules
One side is slightly positive, the other is slightly negative