Monday January 23, 2012 Classwork: #17 Simple Mach Quiz #18 Quiz Corrections #19 Intro to Electricity Lecture Notes #20 Vocab practice Homework: #20 Vocab Practice \ #18 Quiz Corrections Warm Up Electrons have a a.Positive charge and protons have a negative charge b.Negative charge and protons have a positive charge c.Neutral charge d.Negative charge and protons have a neutral charge

How does an atom become electrically charged? When an atom gains or loses an electron

What is Electricity? Like charges repel and opposite charges attract Electric Charge – like charges repel and unlike charges attract – Created through loosing or gaining electrons – An atom that gains an electron is negatively charges – An atom that looses an electron is positively charged

How do you create a charge? Atoms are typically neutral charge, but they can become charged in 3 ways – Friction – electrons are wiped from one object to another through rubbing surfaces – Conduction – electrons move from 1 object to another through direct contact – Induction - charges in uncharged metal are rearranged without touching Conservation of Electric Charges – electrons are not lost or created, they just move from 1 atom to another

Moving Charges Electrical Conductors – material where charges move easily Electrical insulator – material where charges cannot move easily Static electricity – charges at rest on an object Electric discharge – loss of static electricity as charges move off an object Lightening is an example of moving charges

Lightening is an example of attracting electrical charges

#20 Vocab Practice

Tuesday January 24, 2012 Classwork: #21 Current Notes #22 Intro to Electricity Review Homework: Complete # 22 Warm Up Which of the following statements is correct? a.Like charges attract and unlike charges repel b.Unlike charges attract and like charges repel c.Unlike and like charges attract d.Unlike and like charges repel

Electrical current – the rate that charges pass a given point When you turn on a switch you command electrons to move forward instantly Measured in amperes or AMPS There are 2 kinds of current: AC & DC AC -alternating current, electrons can move in both directions EX: your house electricity DC – direct current, electrons travel in same direction only EX: batteries Electrons want to move forward because of voltage – the amount of energy required to move electrons forward More voltage = higher current Resistance – opposition to current flowing Insulators have high resistance

Wednesday January 25, 2012 Classwork: #23 Circuit Prediction Guide #24 Magic School Bus Gets Charged Warm Up Which of the following materials serve as an insulator? a.Copper b.Iron c.Aluminum d.rubber

#23 Prediction Guide Divide you paper in half Prediction Before VideoAfter Video Draw what you think a circuit looks like What do you think the main parts of a circuit are? Why do you think light switches are important?

#24 Magic School BUS Gets Charged

#23 Prediction Guide Fill in the other side of your prediction guide! Prediction Before VideoAfter Video Draw what you think a circuit looks like What do you think the main parts of a circuit are? Why do you think light switches are important?

Thursday January 2, 2012 Classwork: #25 READ & Section Review pg 499 #1-5 & 7 Warm Up In which type of current to charged particles flow in only one direction? a.AC b.DC c.Voltage d.Amperes

Friday January 27, 2012 Classwork: #27 Circuit Notes #28 Circuit Practice Homework: None Warm Up Which of the following describes the method of creating a charge by wiping electrons from one object onto another? a.Conduction b.Convection c.Induction d.Friction

#27 Circuit Notes Electric circuits – complete closed path through which electric charges flow All circuits have 3 basic parts – load, energy source & wires – Load – radio, fan, transforms electrical energy into another energy – Energy source – outlets, batteries – Also have switch – used to open or close circuit

Series circuit – all parts are connected in a single loop Only 1 path for electricity to flow Adding more bulbs will reduce the brightness of each bulb If any lightbulb goes out or turns off none of the others would work Parallel circuit – loads are connected side by side Electricity branches off to each bulb – Keeps brightness the same no matter how many bulbs Benefit – that each load can work individually of others

Circuit Safety If wires get frayed It can cause the resistance to increase, and the circuit can heat up and fail If a circuit has too many loads it can also overheat (possible fire!) Fuses & circuit breakers have thin metal strips that melt and break the circuit if over heated

1.Describe some disadvantages to using a series circuit. 2.Draw a series circuit with 3 different loads on it. 3.Will the series circuit that you drew work well? Why or Why Not? 4.Draw a parallel circuit with the same 3 loads in it. 5.Why would the parallel circuit you drew work better than the series circuit