Electric Charge and Force Chapter 16 - 1 Electric Charge and Force
Bill Nye clip on electricty
Electricity! What is it? Telephone – microphone changes sound waves into electric currents
Electricity Light shinning into a room
Electricity Step on a pin – electrical pulses to and from the brain Electric fence video – Youtube Brainiac
Electric Charge Electric Charge – an electrical property of matter that creates electric and magnetic forces and interactions
Positive and Negative Charge Protons: + Neutrons: 0 Electrons: -
Transferring Charge Walking on the carpet - electrons transferred from the carpet to your shoes Shoes - excess of electrons; become negatively charged Carpet - lost electrons; has an excess of positive charge
Charge The difference in the number of protons and electrons determines the charge
Positive Charge Fewer electrons than protons
Negative Charge Fewer protons than electrons
SI Unit The SI unit for an electric charge is a coulomb or C. Proton 1.6 x 10-19C Electron -1.6 x 10-19C
Conductors and Insulators Transfer of electrons Material in which electrons are able to move easily – conductor Metals
Insulators Material in which electrons are not able to move easily – insulator Plastics
Transfer of Electrons Objects are charged by a transfer of electrons Protons and neutrons are fixed
Static Electricity Accumulation of excess electric charge on an object (depends on material) - static electricity Charging by friction
Static Electricity
Lightning Large static discharge Static discharge between cloud and ground
Thunder Lightning - generates powerful sound waves Heat - causes air to expand rapidly, producing sound waves
Lightning Facts http://www.dirjournal. com/info/interesting- facts-about-lightning/
Charged by Contact When a negative charged object touches a neutral object Electrons will transfer Transfer give a negative charge
Charges move within uncharged objects Negative charged object touches a neutral object Electrons move to the back of the object Induced charge
Conservation of Charge Law of Conservation of Charge - charge can be transferred from object to object, but it cannot be created or destroyed
Polarization Comb and paper Electrons in paper cannot move freely – insulator Charged comb moves molecules in paper – induces charge One side is slightly more positive or negative
Opposite charges attract Charges Exert Forces Unlike charges attract Like charges repel Depends on distance apart Opposite charges attract Like charges repel
Electric Fields Electric Field - surrounds every electric charge Exerts the force that causes other electric charges to be attracted or repelled
Electric Fields Any charge that is placed in an electric field will be pushed or pulled by the field
Electric Force Electric Force – force of attraction or repulsion between objects due to charge