Electric ChargeElectric Charge

• Static ElectricityStatic Electricity is the is the accumulation of excess electric accumulation of excess electric charge on an object.charge on an object.

Click Here for a Static Electricity Example

Electric ChargeElectric Charge

• This occurs This occurs when when electrons electrons are transferred are transferred from one atom from one atom to another.to another.

[http://www.school-for-champions.com/science/images/static1.gif]Click here for an Interactive Example

Electric ChargeElectric Charge

•All electric All electric charges charges (positive or (positive or negative) are negative) are surrounded surrounded by an by an electric electric fieldfield..

[http://www.school-for-champions.com/science/images/electrical_charges2.gif]

Electric ChargeElectric Charge

• These These electric electric fields can fields can cause other cause other charges to charges to move.move.

[http://wps.prenhall.com/wps/media/objects/476/488316/Instructor_Resources/Chapter_04/FG04_07.JPG]

Click here for an Interactive Simulation

[http://www.sciencebuddies.org/mentoring/project_ideas/Elec_img022.jpg]

[http://www.cartoonstock.com/lowres/rjo0224l.jpg]

Changing Electric Changing Electric ChargeCharge

• Law of Law of Conservation of Conservation of ChargeCharge

• Charges can not Charges can not be created or be created or destroyed, they destroyed, they can only be can only be transferred from transferred from object to object.object to object.

[http://images.encarta.msn.com/xrefmedia/sharemed/targets/images/pho/t052/T052289A.jpg]

Changing Electric Changing Electric ChargeCharge

•Electric charge can be Electric charge can be transferred by contact if two transferred by contact if two charged objects are charged objects are touching.touching.

•This is called This is called charging by charging by contactcontact or or conductionconduction.

[http://sol.sci.uop.edu/~jfalward/physics17/chapter8/ballandnrodcopy.jpg]

Notice both end up with the same

charge and repel

Changing Electric Changing Electric ChargeCharge

• InductionInduction occurs when a occurs when a charged object rearranges charged object rearranges the electrons on a neutral the electrons on a neutral object.object.

Still is “neutral” but attracted to

negative!

Ground

[http://peswiki.com/images/7/7d/City_Lightning_400pxw.jpg]

LightningLightning

• Currents in Currents in clouds cause clouds cause charges to charges to become become separatedseparated

[http://www.windows.ucar.edu/earth/Atmosphere/images/tstorm_charges.jpg]

LightningLightning

• Negative Negative charges in charges in cloud cloud induceinduce a positive a positive charge on the charge on the groundground

[http://www.windows.ucar.edu/earth/Atmosphere/images/tstorm_charges.jpg]

LightningLightning

• When the When the charges in cloud charges in cloud and ground and ground become strong become strong enough, they enough, they attract one attract one another causing another causing the “spark” we the “spark” we seesee..

[http://www.windows.ucar.edu/earth/Atmosphere/images/tstorm_charges.jpg]

LightningLightning

• Intra-cloud Intra-cloud lightninglightning never touches never touches the ground, the ground, but is 10 but is 10 times more times more common.common.