Presentation on theme: "Electrostatics Energy at rest - study of nonmoving electric charge."— Presentation transcript:
1 Electrostatics Energy at rest - study of nonmoving electric charge. Static Electricity.InvolvesElectric chargesForces between themTheir behavior in material
2 Form of Energy Atoms – electrons Energy associated with electrons that move from one place to another.
3 Electric Charge/Force Charge – gain/loss of e-.Force – when charge particles come near one another.Rule: “Like charges repel, unlike attract”
4 Electric Fields Region surrounding charged particles. Strength as distance of particle
5 Charged ParticlesIon - a charged atom caused by an imbalance of p+ and e-.positive ions have lost e-negative ions have gained e-The amount of energy required to tear an electron away from an atom varies for different substances.
6 Triboelectric Series Positive Rabbit’s furGlassWoolCat’s furSilkFeltCottonWoodCorkRubberCelluloidNegativeRanks materials according to their tendency to give up their electrons.THE TRIBOELECTRIC SERIES
7 Law of ConservationConservation of Charge - electrons are neither gained nor destroyed, but are simply transferred from one material to another.
8 Coulomb Metric unit for electric charge (C). The symbol for charge is (q).One Coulomb is the charge of 6.24 x 1018 electrons – about the charge going thru a 100 watt light bulb in about 1 second.
9 Coulomb’s LawFor charged particles, the force between the charges varies directly as the product of the charges and inversely as the square of the distance between them.Fel = kq1q2d2k = x N-m2/C2
10 Methods of Charging Build up of electric charges. Methods Friction ConductionInduction
11 ConductionConductors - materials where the outer electrons are not anchored to the nuclei of a particular atom, but are free to roam.Insulators - materials where the outer electrons are tightly bound to the nuclei and remain with a particular atom, they are not free to roam.
12 Semi-ConductorsMaterials which are good insulators in pure crystalline form, but conduction tremendously increases when an impurity has been added.Examples: germanium and silicon.Uses: transistors and diodes.
13 SuperconductorsCertain materials (metal alloy and ceramics) that acquire infinite conductivity (zero resistance to the flow of charge) at temperatures near absolute 0.Examples: Mercury, Niobium-Tin, Lanthanum-Barium-Copper Oxide, and Yttrium-Barium-Copper Oxide.
14 InductionElectrons will move in the conduction surface of an object when a charged object is near it. Excess electrons in the conduction surface will transfer onto another surface.Brings opposite charges
15 Lightning Electric discharge. Loss of static electricity as electric charges move off an object.Grounding – lightning rod