Electrostatics How can an object be charged and what affect does that charge have upon other objects in its vicinity?

Essential Questions for Electrostatics What makes up all matter? What does it mean to be “charged”? What is GROUNDING? What are the (names &) methods of charging? What are insulators & conductors? Hey wait, what IS charge? A measurement, a concept….? What do charged objects do? (to other objects)

Electric Charge Matter is made of Neutrons, Protons and Electrons Protons have POSITIVE charge Electrons have NEGATIVE charge Neutrons are uncharged Which has “more” charge? Which charges move to charge an object? Why do they move?

Grounding (UN-CHARGING) This term is used for the process that “un- charges” a charged object. It is performed by contacting a charged object to an object that can give, OR receive ___________ charges, so that the initially charged object is made neutral. It can (partially) happen w/o contact when one object that is highly charged discharges across a gap – that is a spark

Charging an Object Charging by : Friction Conduction Induction Materials rubbed “against” each other transfer … Conduction A charged object is brought in contact with a conductor and there is a transfer of … Induction A charged object is brought NEAR a conductor, the conductor is grounded, there is a transfer of….. the ground is removed, and finally the charged object is moved away from the conductor Polarization (not really charging, as a polarized object’s NET charge can be zero) A charged object is brought near a neutral conductor, electrons on the conductor move (toward, or away from the charged object) and then the polarized object behaves as if it has the ________ charge as the object that caused the polarization.

Conductors and Insulators A good CONDUCTOR allows negative charges to travel around through the material making up the conductor, with very little RESISTANCE. A good INSULATOR makes it very hard for negative charges to travel around through the material making up the insulator. These have a lot of RESISTANCE. A SUPERCONDUCTOR is a material that allows negative charges to flow through it without any RESISTANCE.

Conductors and Insulators

Conductors and Insulators

Quantity of Charge The SI unit for charge is the COULOMB (C) The charge of one electron is -1.6x10-19C The charge of one proton is +1.6x10-19C The quantity of charge equal to 1.6x10-19C is often written as e so the charge of one electron is –e To calculate the charge of a certain number of electrons or protons, use the equation: Q = +ne where Q is quantity of charge, and n is the # of charge carriers

Quantity of Charge Q = +ne To calculate the charge of a certain number of electrons or protons, use the equation: Q = +ne where Q is quantity of charge, and n is the # of charge carriers

Behavior of Charge and “Charged” Objects Opposite charges attract and like charges repel Charged objects can attract neutral objects, by polarizing the neutral objects. Electrons are the only charges to get transferred The force between charged objects can be mathematically described by Coulomb’s Law

Assignment Electroscope Investigation PCR Static Electricity Lessons 1&2 CYU Lesson 1: a(1), b(1-6), c(all), d(1-3), e(1,2,4,5,6) Lesson 2: a(3,4), b(4), c(all), d(all)