1. Chapter 17 Section 1 Electric Charge & Force
What are the different kinds of electric charge?
How do materials become charged?
What force is responsible for most everyday forces?
Chapter 17 Section 1 Electric Charge & Force pp

2. A. Charge and Force FORCE
Electric charges ( ____ and ____) exert a _________.
e p+
FORCE
A force of ______________ exists between opposite charges ( ____ and ____ )…and a force of ____________ exists between particles/objects of the same charge.
Force depends on: CHARGE and DISTANCE
ATTRACTION
e p+
REPULSION
RULE OF CHARGES =
“_______________________________________________”
opposite charges attract…like charges repel

3. Opposite charges attract
Like charges repel

4. Electric Fields:
Regions of force around charged particles/objects (+) or (-)
Force is exerted on other charged particles/objects
Force is strongest NEAR the charged particles/objects
Field lines never cross one another

5. C. Static Electricity *The word static means: _______________
not moving, stationary
Static electricity:
electrons
The movement of charges ( _________ ) from one object to another without further movement.
A neutral object gets an electric charge when it either gains or loses __________
electrons
*Each atom gains/loses 1, 2, 3…electrons
POSITIVE
-When the # of p+ > # of e- = _______________ (lost e-)
-When the # of p+ < # of e- = _______________ (gained e-)
NEGATIVE

7. 3 ways of charging an object
(becoming (+) or (-))
Method
Definition
Illustration

8. FRICTION:
Two objects are rubbed together. One object loses e-, one object gains e-. e-

10. 2. CONDUCTION: Charging an object through direct contact (touching)
e- move from one object to another

11. Conductors are materials which allow electrons to flow freely from atom to atom
(METALS, WATER)
Insulators are materials which DO NOT allow electrons to flow from atom to atom
(PLASTIC, RUBBER)

12. e- attract or repel (move within the neutral object)…
3. INDUCTION
NO CONTACT!
electrons rearrange within a neutral object when a charged object approaches it.
e- attract or repel (move within the neutral object)…
p+ do not move!!!

13. Plastics Silk Rubber D. Materials used to study static electricity:
lose e- (become +)
gain e- (become -)
Rabbit fur
Glass
Human hair
Sheep's wool
Human skin
Plastics
Silk
Rubber

14. Used to detect an electric charge
Electroscope
Used to detect an electric charge
Leaves hang down when no charge
Repel when have the same charge
Electrons move into the leaves (-) or away from the leaves (+)

15. Electroscope Animations: Conduction vs. Induction

16. PITH BALL Cork/foil, hangs from a string
Can be charged + or -, then moves freely and attracts or repels object

17. Van de Graaff Generator

18. After drying cloths in the clothes dryer, you may notice they stick together. Explain this “static cling”. Will there be more “static cling” if all of the clothes in the dryer are of the same or different materials? Explain.