ED/GC 595 – Earth System Science: Inquiry Across Scientific Disciplines Dr. Dave Donovan, Professor of Physics, NMU. Marquette, MI June 2009

Physics Standards Grades Grade 3 – Changes in Motion – Light and Sound Grade 4 – Heat, Electricity, and Magnetism Grade 5 – Measuring Changes in Motion – Position and Motion of Objects in the Sky

Physics Standards Grades 3 – 7 (Cont) Grade 6 – Matter and Energy – Plate Tectonics and Fossils Grade 7 – Waves and Energy

Content Statements and Expectations for Heat, Electricity and Magnetism

_Science_GLCE_ _218314_7.pdf Page 43 – 45

Charge is a fundamental property of matter that indicates how the matter will behave in an electric or a magnetic field. Unit of Charge is the Coulomb, 1 electron has a charge of -1.6 x C. => 1 C requires e - s There are two types of Charge: Positive(+) and Negative(-) Ben Franklin first proposed the laws of Charge – Like Charges Repel – Opposite Charges Attract Most objects are charged by an excess (-) or a deficiency (+) of electrons.

Fld.jpeg

science.co.uk/Physics_GCSE/ Physics_AQA/Physics_1B/Radiation_E_Field.GIF E Field going from top to bottom, High Voltage to Low Voltage

odules/m7/images/Image1234.gif B Field going into Paper Positively Charged (+) Particle Negatively Charged (-) Particle

er/images/cyclotron_animated.gif

Current is the amount of charge which moves past a given reference point in a given amount of time. The unit of Current is the Ampere. 1 A = 1 C/s Voltage is the amount of Electrical Potential Energy per unit Charge at a point. The unit of Voltage is the Volt. 1 V = 1 J/C. J (Joule) is a unit of energy. 1 J is the amount of energy a 2 kg mass has when moving 1 m/s, or J is the energy needed to heat 1 g of water 1˚C. (ie J is 1 Calorie)

Current goes from Higher Voltage (more +) to Lower Voltage (more -). + Charges are repelled by Higher (+) Voltages and attracted to Lower (-) Voltages. - Charges are attracted to Higher (+) Voltages and repelled by Lower (-) Voltages. Currents are defined by the direction a (+) charge would take in a circuit.

Water Analogy of Electricity Current is analogous to Water Flow (ie how much water flows in the pipe?). Voltage is analogous to Water Pressure (ie how much energy does the water in the pipe have?). Resistance is the opposition to current flow. It is analogous to impediments in the pipe, debris, friction, changes in pipe diameter, etc.

ricity/images/circuit_analogy_water_pipes_sm.jpg

s_work_and_why_they_blow_up/how_batteries_work_figure02.jpg

magnets.com/images2/00020.jpg

Large Current, Small Voltage Similar to water flowing on the ground. Little Damage (Work) done!

swac.com/owen/caglesdam3.jpg

AAAAAAF8/Jc2N0JTyYLc/s400/birds+on+a+wire.jpg

Small Current, Large Voltage Similar to water drop dropped from large height. Little Damage (Work) done!

4pPYzHV_fs.jpg

champions.com/science/images/static_sparks-finger.jpg

Large Current, Large Voltage Similar to water flowing on the ground from a great height. Significant Damage (Work) done!

content/uploads/2008/05/waterfall3.jpg

bin/showfile.exe?CISOROOT=/spphotos&CISOPTR=450

lightning2a7z.jpg

An Electrical Circuit is a collection of Electrical Elements connected together. Electrical Elements are Power Providers (Batteries), Power Using Devices (Lights, motors, etc), and Connective Elements (Wires). A circuit will have electrical current flow through it only if the circuit is complete. The circuit begins on or at a High Voltage point and it must end on or at a Low Voltage point. Often these are two parts of a Power Providing Device.

A Simple Circuit

i (current) High Voltage Low Voltage i (current) Power Providing Power Using