Chapter 17 Electric Forces and Fields Section 1

Chapter 17 Electric Forces and Fields Section 1 & 2

Properties of Electric Charge There are two kinds of electric charge : positive and negative. Like charges repel & unlike charges attract.

Electric Charge is Conserved When a balloon is rubbed against your hair, some of your hair’s electrons are transferred to the balloon. The positive charge on your hair is equal in magnitude to the negative charge on the balloon.

Electric Charge is Quantized When an object is charged, its charge is always a multiple of a fundamental unit of charge : e This means charge is quantized.

Transfer of Electric Charge Conductors : material in which electric charges move freely. › Ex: (most metals) copper, aluminum Charge can be done by › Contact ex: A balloon becomes charged when you rub it on your hair. › Induction ex:

Transfer of Electric Charge Insulators : materials in which electric charges do not move freely. › Ex: glass, rubber, silk, plastic Charge can be done by contact or polarization. Polarization ex:

Electric Force Electric force is a field force between two charged objects causing motion either toward or away from each other. The closer two charges are, they greater the force between them. This is represented by Coulomb’s Law.

Formula : Coulomb’s Law F electric = Newtons (N) k. C = 8. 99 x 10 9 q = Coulomb (C) r = meters (m)

Guided Practice Open books to pg. 635 Sample Problem 17 A