Presentation is loading. Please wait.

Presentation is loading. Please wait.

Electrostatics Ch 32 & 33.

Similar presentations

Presentation on theme: "Electrostatics Ch 32 & 33."— Presentation transcript:

1 Electrostatics Ch 32 & 33

2 Basic Concept In Mechanics, the basic property of matter is Mass.
In Electricity, the basic property is Charge.

3 Basic Units Compare Smallest Possible Unit Practical Unit US Currency
Penny $0.01 = 1/100th of a dollar Dollar $1 = 100 Pennies Electric Charge Elementary Charge (1e) electron or proton 1e = 1.6 x 10-19C Coulomb 1C = 6.25 x 1018e

4 Examples How many electrons are on a conductor if it has a charge of -4 x C? 250 electrons What charge will 120 protons have? 1.92 x C

5 Example Why is it not possible for any object to have a charge of 8 x C? Electrons (or protons) cannot be broken down into smaller pieces.

6 Movement of Charge Conductors Insulators Electrons are free to move
Most metals Insulators Electrons are not free to move

7 Basic Concept Opposite Charges Attract Like Charges Repel + - - - + +

8 Movement of Charge Grounding Examples
Charges on an object will try to move away from like charges or towards opposite charges Examples Lightning, Static electricity

9 Charging by Contact When 2 conductors of unequal charges touch, the electrons will move to balance out the charge, leaving both conductors with the same charge

10 Charging by Induction If a charged object is brought near a conducting surface, even without physical contact, electrons will move in the conducting surface. Read 32.6

11 Charging by Induction


13 Review Gravitational Force What factors affect gravitational force?
Size of each mass Distance of separation

14 Electrostatic Force What factors will affect the amount of attraction or repulsion? Size of each charge Distance of separation

15 Coulomb’s Law k = Electrostatic constant, 8.99 x 109 Nm2/C2
q = charge (C) r = distance separating the center of each charge (m)


17 Electric Fields Electric Field is a region around a charged object through which a force is exerted on any other charged particle. Electric Field Lines are imaginary lines drawn to show electric field

18 - Electric Field Lines + Lines are not real Positive  Negative
Can not cross Closer lines mean stronger field - +

19 Electric Fields Parallel Plates
Electric Field is uniform between plates

20 Electric Field Strength, E
Force per charge Amount of force felt by a charge Vector E (N/C) Fe (N) q (C)

Download ppt "Electrostatics Ch 32 & 33."

Similar presentations

Ads by Google