Science 9Science 9ElectricityElectricity

Static Electric ChargeStatic Electric Charge

Static Electric Charge (9-2)Static Electric Charge (9-2)

Static electric Static electric charge-charge- A charge on a A charge on a

substance that substance that stays in the same stays in the same placeplace

+ -

Examples of Static ChargeExamples of Static Charge Lightning-Lightning-(9-10)(9-10)

http://www.youtube.com/watch?v=gKPwkau0Dh0&feature=related

http://www.youtube.com/watch?v=HLcFHo2HR7I&feature=related

Static cling-Static cling-

Examples of Static ChargeExamples of Static Charge Static shock-Static shock-

Producing Static ElectricityProducing Static Electricity Charge by Friction-Charge by Friction- (9-3) (9-3)

Electric charge is transferred by rubbing Electric charge is transferred by rubbing object togetherobject together

Producing Static ElectricityProducing Static ElectricityWe know which We know which

object will cause object will cause which charge which charge when caused by when caused by friction using the friction using the Electrostatic Electrostatic SeriesSeries

(9-3)(9-3)

(Items above become (Items above become negatives) negatives)

Rubber Rubber Ebonite Ebonite Polyethylene Polyethylene cotton cotton silk silk wool wool glass glass acetate acetate fur/hair fur/hair (Items below become (Items below become

positives) positives)

Producing Static ElectricityProducing Static Electricity Charge by conduction (contact)- (9-5)Charge by conduction (contact)- (9-5)

Charge is transferred by touching a Charge is transferred by touching a charged object to an uncharged objectcharged object to an uncharged object

http://www.shep.net/resources/curricular/physics/P30/Unit2/electroscope.swf

Producing Static ElectricityProducing Static Electricity Charge by induction- (9-8)Charge by induction- (9-8)

Neutral object becomes charged when a Neutral object becomes charged when a charged object is brought near it.charged object is brought near it.

Induced charge can become more Induced charge can become more permanent if a ground wire is attached to it. permanent if a ground wire is attached to it.

http://www.shep.net/resources/curricular/physics/P30/Unit2/electroscope.swf

Laws of Electric Charge (9-Laws of Electric Charge (9-2)2)

Unlike charges attract one anotherUnlike charges attract one another Like charges repel one anotherLike charges repel one another

Removing Static Electricity Removing Static Electricity (9-7)(9-7)

Discharge (neutralize)-Discharge (neutralize)- When excess electric charge is removed When excess electric charge is removed

from an object.from an object. Discharge can be quick and explosive (lightning)Discharge can be quick and explosive (lightning) Discharge can be unnoticed (fabric softener Discharge can be unnoticed (fabric softener

sheet)sheet)

http://www.youtube.com/watch?http://www.youtube.com/watch?v=R7cgazVkhTk&feature=related v=R7cgazVkhTk&feature=related

Removing Static ElectricityRemoving Static Electricity GroundingGrounding

Connecting the object to the earthConnecting the object to the earth The charge is shared with the entire earthThe charge is shared with the entire earth

Discharge at a pointDischarge at a point Objects made into a point have Objects made into a point have

electrons pushed off the end.electrons pushed off the end.

Detecting Static ChargeDetecting Static Charge ElectroscopeElectroscope -a device used to detect -a device used to detect

the presence of charge. (9-4) the presence of charge. (9-4) usually constructed with a metal plate or usually constructed with a metal plate or

sphere at the top of a metal post with thin sphere at the top of a metal post with thin foil leaves hanging from the bottom of the foil leaves hanging from the bottom of the post post

http://www.regentsprep.org/Regents/http://www.regentsprep.org/Regents/physics/phys03/aeleclab/nerscope.htm physics/phys03/aeleclab/nerscope.htm

Dangers of Static ElectricityDangers of Static Electricity Cause firesCause fireshttp://www.metacafe.com/watch/862578/http://www.metacafe.com/watch/862578/

static_electricity_causes_fire_at_gas_station/ static_electricity_causes_fire_at_gas_station/ Can wreck electronics (need grounding Can wreck electronics (need grounding

wire)wire) Can hurt (shock) or cause death (10-9)Can hurt (shock) or cause death (10-9)http://www.youtube.com/watch?http://www.youtube.com/watch?

v=CpxKEGdfDxI&feature=related v=CpxKEGdfDxI&feature=related

Uses of Static Electricity (9-Uses of Static Electricity (9-8)8)

Electrostatic air cleanersElectrostatic air cleaners Removes dust and other particles by the Removes dust and other particles by the

attraction of unlike chargesattraction of unlike charges Electrostatic spray paintingElectrostatic spray painting

The paint and the object to be painted The paint and the object to be painted are given opposite chargesare given opposite charges

http://video.google.com/videoplay?http://video.google.com/videoplay?docid=-860069260229630847 docid=-860069260229630847

Uses of Static Electricity (9-Uses of Static Electricity (9-11)11)

Fabric softener sheetsFabric softener sheets Allows electric charge to move in Allows electric charge to move in

between clothes instead of building up.between clothes instead of building up. PhotocopiersPhotocopiers Cell phones and car radios Cell phones and car radios