monday january 23, 2012 classwork: #17 simple mach quiz #18 quiz corrections #19 intro to...

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 chargeb.Negative charge and protons have a positive chargec.Neutral charged.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 repelb.Unlike charges attract and like charges repelc.Unlike and like charges attractd.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.Copperb.Ironc.Aluminumd.rubber

#23 Prediction GuideDivide you paper in half

Prediction Before Video After 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 GuideFill in the other side of your prediction

guide!Prediction Before Video After 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.ACb.DCc.Voltaged.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.Conductionb.Convectionc.Inductiond.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