Physics II: Electricity & Magnetism Introduction, Sections 21.1 to 21.5

Physics II:Electricity & Magnetism

Physics II:Electricity & Magnetism

Introduction, Sections 21.1 to 21.5

Introduction, Sections 21.1 to 21.5

Additional Exploratory Topics & Activities


Section 21.2 Activities:Avogadro’s NumberIonic vs. Covalent Bonds (Melting Points and

Conductivity Tests)Compounds & Crystals Structures (Viewing with

Microscope & Online Research:http://cst-www.nrl.navy.mil/lattice/




http://cst-www.nrl.navy.mil/lattice/












Wednesday (Day 1)

Wednesday (Day 1)

Warm-UpWarm-Up

Wed, Jan 21 Pick up the following handouts and find your seat:

JournalSyllabusHomework Expectations PacketStudent Information Sheet“What do you know?” Packet (Part I)Scantron Sheet“Foundational Mathematics’ Skills of Physics” Packet

Place your homework on my desk: Not Applicable


JournalSyllabusHomework Expectations PacketStudent Information Sheet“What do you know?” Packet (Part I)Scantron Sheet“Foundational Mathematics’ Skills of Physics” Packet


Journal entryJournal entry

Wed, Jan 21 Why did you decide to take Physics II: Electricity &

Magnetism?

Wed, Jan 21 Why did you decide to take Physics II: Electricity &

Magnetism?

Essential Question(s)Essential Question(s)

HOW DO WE DESCRIBE THE NATURE OF ELECTROSTATICS AND APPLY IT TO VARIOUS SITUATIONS?What foundational mathematics’ skills are necessary

to be successful in Physics II?How do we describe and apply the concept of electric

field?

HOW DO WE DESCRIBE THE NATURE OF ELECTROSTATICS AND APPLY IT TO VARIOUS SITUATIONS?What foundational mathematics’ skills are necessary

to be successful in Physics II?How do we describe and apply the concept of electric

field?

VocabularyVocabulary

Static ElectricityElectric ChargePositive / NegativeAttraction / RepulsionCharging / DischargingFriction InductionConductionLaw of Conservation of

Electric Charge


Electric Charge

Non-polar MoleculesPolar Molecules Ion Ionic CompoundsForceTest ChargeElectric FieldField LinesElectric DipoleDipole Moment


AgendaAgenda Introduction Room Tour

Missing work bin Stapler, 3-Hole Punch, Sharpener, Scissors, etc.

Distribute Daily Journal and Lab Journal Distribute Textbooks

Physics Book on top Discuss Syllabus, and HW/Journal/Lab Expectations Web Assign Complete the following

Student Information Sheet“What do you know?” Packet (Part I) on Scantron

Introduction Room Tour

Missing work bin Stapler, 3-Hole Punch, Sharpener, Scissors, etc.

Distribute Daily Journal and Lab Journal Distribute Textbooks

Physics Book on top Discuss Syllabus, and HW/Journal/Lab Expectations Web Assign Complete the following

Student Information Sheet“What do you know?” Packet (Part I) on Scantron

Mr. Roe’sBackground Information

Mr. Roe’sBackground Information

InterestsPhysics Club - After School on ThursdaysUndergraduate - IUP

B.S. in Physics EducationB.S. in Chemistry Education

Graduate – BloomsburgM.S. in Instructional Technology

InterestsPhysics Club - After School on ThursdaysUndergraduate - IUP

B.S. in Physics EducationB.S. in Chemistry Education

Graduate – BloomsburgM.S. in Instructional Technology

Distribute TextbooksRoom Tour

Missing work binStapler, 3-Hole Punch, Sharpener, Scissors, etc.

Distribute TextbooksRoom Tour

Missing work binStapler, 3-Hole Punch, Sharpener, Scissors, etc.

Syllabus - HighlightsSyllabus - Highlights

web: http://plutonium-239.comTutoring HoursDue dates Resources Intouch

email: [email protected]

web: http://plutonium-239.comTutoring HoursDue dates Resources Intouch

email: [email protected]

http://staff.wssd.k12.pa.us/aroe/

mailto:[email protected]


http://staff.wssd.k12.pa.us/aroe/



Physics TextbooksPhysics Textbooks

Physics II - Electricity and Magnetism“Physics for Scientists and Engineers with Modern

Physics” (Giancoli)

Physics II - Electricity and Magnetism“Physics for Scientists and Engineers with Modern

Physics” (Giancoli)

Physics II - Electricity and Magnetism


ElectrostaticsCharge, Field, and PotentialCoulomb’s Law and Field and Potential of Point

ChargesFields and Potentials of Other Charge DistributionsGauss’s Law

Conductors, Capacitors, DielectricsElectrostatics with ConductorsCapacitorsDielectrics

ElectrostaticsCharge, Field, and PotentialCoulomb’s Law and Field and Potential of Point

ChargesFields and Potentials of Other Charge DistributionsGauss’s Law

Conductors, Capacitors, DielectricsElectrostatics with ConductorsCapacitorsDielectrics



Electric CircuitsCurrent, Resistance, PowerSteady-State Direct Current Circuits with Batteries and

Resistors OnlyCapacitors in Circuits

MagnetostaticsForces on Moving Charges in Magnetic FieldsForces on Current-Carrying Wires in Magnetic FieldsFields of Long Current-Carrying WiresThe Biot-Savart Law and Ampere’s Law

Electric CircuitsCurrent, Resistance, PowerSteady-State Direct Current Circuits with Batteries and

Resistors OnlyCapacitors in Circuits

MagnetostaticsForces on Moving Charges in Magnetic FieldsForces on Current-Carrying Wires in Magnetic FieldsFields of Long Current-Carrying WiresThe Biot-Savart Law and Ampere’s Law



ElectromagnetismElectromagnetic InductionInductance (LR, LC, and LRC Circuits)Maxwell’s Equations in Integral FormElectromagnetic Waves

Additional Topics:Waves (Light, Sound, etc.)Mirrors and Lenses

ElectromagnetismElectromagnetic InductionInductance (LR, LC, and LRC Circuits)Maxwell’s Equations in Integral FormElectromagnetic Waves

Additional Topics:Waves (Light, Sound, etc.)Mirrors and Lenses

Physics II Weighted Scale:Physics II Weighted Scale:

35%: Tests & Projects10%: Quizzes30%: *Homework / Class Work

*http://www.webassign.net Username: lastnamefirstinitial (roes)Institution: cedarcliff.paPassword: ccphysics

15%: Laboratories / Lab Reports10%: Journal

35%: Tests & Projects10%: Quizzes30%: *Homework / Class Work

*http://www.webassign.net Username: lastnamefirstinitial (roes)Institution: cedarcliff.paPassword: ccphysics

15%: Laboratories / Lab Reports10%: Journal

SummarySummary

In regards to Electricity & Magnetism, write down: 3 things you already knew from today2 things that you learned today1 thing you would like to know

HW (Place in your agenda): Student Information Sheet“What do you know?” Packet (Part I) on Scantron


HW (Place in your agenda): Student Information Sheet“What do you know?” Packet (Part I) on Scantron

Thursday (Day 2)

Thursday (Day 2)

Section 21.1Section 21.2


Journal EntryJournal Entry

Thurs, Jan 22 What is the charge of a proton? What is the charge of an electron? What happens to a _______ charge when a _______ charge is

around it? positive; negative positive; positive negative; negative negative; positive

Place your homework on my desk: Student Information Sheet “What do you know?” Packet (Part I) & Scantron

Thurs, Jan 22 What is the charge of a proton? What is the charge of an electron? What happens to a _______ charge when a _______ charge is

around it? positive; negative positive; positive negative; negative negative; positive

Place your homework on my desk: Student Information Sheet “What do you know?” Packet (Part I) & Scantron

Warm-UpWarm-Up


“Foundational Mathematics’ Skills of Physics” Packet



“Foundational Mathematics’ Skills of Physics” Packet



WHAT PRIOR FOUNDATIONAL MATHEMATICS’ SKILLS ARE NECESSARY IN PHYSICS II?

HOW DO WE DESCRIBE THE NATURE OF ELECTROSTATICS AND APPLY IT TO VARIOUS SITUATIONS?How do we describe and apply the concept of electric field?How do we compare and contrast the basic properties of an

insulator and a conductor?How do we describe and apply the concept of induced charge and

electrostatic shielding?How do we describe and apply Coulomb’s Law and the Principle

of Superposition?





of Superposition?



Electric Charge


Electric Charge



Foundational Mathematics Skills in Physics Timeline


Day Pg(s) Day Pg(s) Day Pg(s) Day Pg(s)

11

26 3 11 16 16 21

213

147 4 12 17 17 8

322

238 5 13 18 18 9

424†12

9 6 14 19 19 10

5 15 10 7 15 20 20 11


AgendaAgenda

Introduction to Electrostatics

Pick up the following handouts:“Foundational Mathematics’ Skills of Physics” Packet“What do you know?” Packet (Part II)

Introduction to Electrostatics

Pick up the following handouts:“Foundational Mathematics’ Skills of Physics” Packet“What do you know?” Packet (Part II)

Chapters 21 & 22

Electric Charge and Electric Field; Gauss’s Law

Units of Chapter 21

• Static Electricity; Electric Charge and Its Conservation

• Electric Charge in the Atom

• Insulators and Conductors

• Induced Charge; the Electroscope

• Coulomb’s Law

• Solving Problems Involving Coulomb’s Law and Vectors

• The Electric Field

Units of Chapter 21 & 22

• Field Lines

• Electric Fields and Conductors

Chaper 22

•Electric Flux

•Gauss’s Law

• Electric Forces in Molecular Biology: DNA Structure and Replication


How do we describe and apply the concept of electric field?How do we describe the characteristics of a

positive electric charge?How do we describe the characteristics of a

negative electric charge? How do we describe the law of conservation of

electric charge?

How do we describe and apply the concept of electric field?How do we describe the characteristics of a

positive electric charge?How do we describe the characteristics of a

negative electric charge? How do we describe the law of conservation of

electric charge?

21.1 Static Electricity; Electric Charge and Its Conservation

Objects can be charged by rubbing

21.1 Static Electricity; Electric Charge and Its

Conservation

Charge comes in two types, positive and negative; like charges repel and opposite charges attract

†Electricity comes from the Greek word elektron, which means “amber”

Can transfer charge from one material to another suitable material simply by rubbing:

A Teflon rod rubbed with fur acquires a negative charge, while the fur becomes positively charged.

This is called charging by friction.

21-1 Electric Charge - a property of matter

21.1 Static Electricity; Electric Charge and Its Conservation

Electric charge is conserved – the arithmetic sum of the total charge cannot change in any interaction.


How do we describe and apply the concept of electric field?How do we describe electric charge in an

atom?How do we describe electric charge in a

molecule (or formula unit)?

How do we describe and apply the concept of electric field?How do we describe electric charge in an

atom?How do we describe electric charge in a

molecule (or formula unit)?


Electric charge, whether we know it or not, is responsible for many familiar phenomena:

• The binding of electrons to a nucleus, forming an atom

• Atoms binding together into molecules

• Atoms or molecules binding together into liquids and solids

• Biological processes

• Chemical reactions

21.2 Electric Charge in the Atom

Atom:

Is electrically neutral

Nucleus (small, massive, positive charge)

Electron cloud (large, very low density, negative charge)

Parts of the AtomParts of the Atom

Location: NucleusProton

Charge: 1.60 x 10-19 CoulombsMass: 1.6726 x 10-27 kgMade of 2 up quarks and 1 down quark

NeutronCharge: Neutral (0 Coulombs)Mass: 1.6749 x 10-27 kgMade of 2 down quarks and 1 up quark

Location: Energy Levels in the Electron CloudElectrons

Charge: -1.60 x 10-19 CoulombsMass: 9.11 x 10-31 kg

Location: NucleusProton

Charge: 1.60 x 10-19 CoulombsMass: 1.6726 x 10-27 kgMade of 2 up quarks and 1 down quark

NeutronCharge: Neutral (0 Coulombs)Mass: 1.6749 x 10-27 kgMade of 2 down quarks and 1 up quark

Location: Energy Levels in the Electron CloudElectrons

Charge: -1.60 x 10-19 CoulombsMass: 9.11 x 10-31 kg

Charge is measured in Coulombs (C); the smallest unit of charge is the magnitude of the charge on

the electron:


The Size of the NucleusThe Size of the Nucleus

Almost all of the mass of the atom is concentrated in its tiny nucleus.

Next Slide: the football field illustration.

Almost all of the mass of the atom is concentrated in its tiny nucleus.

Next Slide: the football field illustration.

If the nucleus were the size of a pinhead . . .

If the nucleus were the size of a pinhead . . .

The Low Density of theElectron Cloud Model

The Low Density of theElectron Cloud Model

The low density of the electron cloud is due to the fact that (1) the mass of one proton is equal to the mass of 1,836 electrons and (2) the electrons are arranged in the energy levels that are far from the nucleus.

The proton has 1,836 times more inertia than an electron and is therefore 1,836 times harder to move than an electron.

The low density of the electron cloud is due to the fact that (1) the mass of one proton is equal to the mass of 1,836 electrons and (2) the electrons are arranged in the energy levels that are far from the nucleus.

The proton has 1,836 times more inertia than an electron and is therefore 1,836 times harder to move than an electron.

INERTIAA Proton vs. an Electron

INERTIAA Proton vs. an Electron

Recall Newton’s Second Law of Motion

Force = mass x acceleration

The proton has 1,836 times more mass (aka. Inertia) than an electron and is therefore 1,836 times harder to move than an electron.

Recall Newton’s Second Law of Motion

Force = mass x acceleration

The proton has 1,836 times more mass (aka. Inertia) than an electron and is therefore 1,836 times harder to move than an electron.

Electron Cloud ModelElectron Cloud Model

The probability of locating an electron 90% of the time is determined by utilizing the Schrödinger equation and statistics.

The probability of locating an electron 90% of the time is determined by utilizing the Schrödinger equation and statistics.

Materials in which the outermost electron(s) that are very loosely bound to the atoms, and can move freely through the material are called conductors.

Most other materials are insulators; some are semiconductors, which will be discussed later


Chemical Bonding

Atoms bond together to form electrically neutral substances.

The type of chemical bond is determined by the electronegativity difference between the atoms involved.

Electronegativity Values:The Affinity for ElectronsElectronegativity Values:The Affinity for Electrons

Electronegativity Values:The Affinity for ElectronsElectronegativity Values:The Affinity for Electrons

Electronegativity Difference and Bond Type

Electronegativity Difference and Bond Type

Electronegativity Difference

Bond Type

EN: 0.0 - 0.4 Nonpolar Covalent Bond (Atoms have no charge)

EN: 0.41 - 1.65 Polar Covalent Bond(Atoms have a partial charge)

EN: 1.66 and greater

Ionic Bond(Ions have a full charge)

Nonpolar Covalent Molecules

Nonpolar Covalent Molecules

Electronegativity Difference: 0.0 - 0.4 Description: Shares electrons evenly Examples: H2, CH4, Cl2, O2, Br2, I2, etc.

They are generally gases at room temperature because they have little or †no attraction to other nonpolar molecules Exceptions:

Bromine (Br2) is a liquid (70 total electrons/molecule)

Iodine (I2) is a solid (106 total electrons/molecule)

†A Temporary Dipoles can establish an attractive force if the molecules (1) get close enough and (2) are not moving fast.

Electronegativity Difference: 0.0 - 0.4 Description: Shares electrons evenly Examples: H2, CH4, Cl2, O2, Br2, I2, etc.

They are generally gases at room temperature because they have little or †no attraction to other nonpolar molecules Exceptions:

Bromine (Br2) is a liquid (70 total electrons/molecule)

Iodine (I2) is a solid (106 total electrons/molecule)

†A Temporary Dipoles can establish an attractive force if the molecules (1) get close enough and (2) are not moving fast.

Temporary DipoleTemporary Dipole

Polar Covalent MoleculesPolar Covalent Molecules Electronegativity Difference: 0.41 - 1.65 Description: Shares electrons unevenly Examples: H2O, NH3

They are generally liquids or solids at room temperature because their permanent dipoles (slightly positive and slightly negative parts) attract their counterparts of other polar molecules and †many polar molecules are able to group together. Example: Water Droplets

†

Electronegativity Difference: 0.41 - 1.65 Description: Shares electrons unevenly Examples: H2O, NH3

They are generally liquids or solids at room temperature because their permanent dipoles (slightly positive and slightly negative parts) attract their counterparts of other polar molecules and †many polar molecules are able to group together. Example: Water Droplets

†1 drop x

1 mL

20 dropsx

1 g

1 mLx

1 mole

18.02 gx

6.022x1023 molecules

1 mole=

21.2 Electric Charge in the Atom

Polar molecule: neutral overall, but charge not evenly distributed

Dipole-Dipole BondingDipole-Dipole Bonding

Dipole-Dipole BondsDipole-Dipole Bonds

Ionic Compounds(aka. Formula Units)

Ionic Compounds(aka. Formula Units)

Electronegativity Difference: 1.66 and above Description: “†Transfers” electrons from one atom to another

creating an attraction due to the charge of each atom. Examples: NaCl, CaCl2, MgO, KI, CuCl2 They are solids at room temperature because their

†permanent positive charges attract all other negative charges and a negative charge is attracted to all of the positive charges. This creates a large repeating structure known as a crystal lattice.

†In reality, the electron that has been transferred is still being attracted by the nucleus of the atom that has “lost” the electron, but the ratio of this attraction to the atom that has gained it is relatively small. i.e. Cl-/Na+: 3.16/0.93 ≈ 3; The transferred electron is attracted 3 times

more to the Cl ion than the Na ion.

Electronegativity Difference: 1.66 and above Description: “†Transfers” electrons from one atom to another

creating an attraction due to the charge of each atom. Examples: NaCl, CaCl2, MgO, KI, CuCl2 They are solids at room temperature because their

†permanent positive charges attract all other negative charges and a negative charge is attracted to all of the positive charges. This creates a large repeating structure known as a crystal lattice.

†In reality, the electron that has been transferred is still being attracted by the nucleus of the atom that has “lost” the electron, but the ratio of this attraction to the atom that has gained it is relatively small. i.e. Cl-/Na+: 3.16/0.93 ≈ 3; The transferred electron is attracted 3 times

more to the Cl ion than the Na ion.

Crystal Lattice: NaClCrystal Lattice: NaCl











SummarySummary


HW (Place in your agenda): “Foundational Mathematics’ Skills of Physics” Packet

(Page 1 & 2)

TEACHER HOMEWORK: BUY MYLAR BALLOONS AND SCOTCH TAPE



(Page 1 & 2)

TEACHER HOMEWORK: BUY MYLAR BALLOONS AND SCOTCH TAPE

Friday (Day 3)Friday (Day 3)



Warm-UpWarm-Up

Fri, Jan 23 Identify the three bond types and their characteristics

Pickup a LAB JOURNAL from my desk.

Place your homework on my desk:“Foundational Mathematics’ Skills of Physics” Packet

(Page 1 & 2)

Fri, Jan 23 Identify the three bond types and their characteristics

Pickup a LAB JOURNAL from my desk.

Place your homework on my desk:“Foundational Mathematics’ Skills of Physics” Packet

(Page 1 & 2)






of Superposition?





of Superposition?



Electric Charge


Electric Charge






11

26 3 11 16 16 21

213

147 4 12 17 17 8

322

238 5 13 18 18 9

424†12

9 6 14 19 19 10

5 15 10 7 15 20 20 11


AgendaAgenda

Review “Foundational Mathematics’ Skills of Physics” Packet (Page 1 & 2) with answer guide in the back of the class

Introduction to Insulators and conductors

Begin Electrostatics Lab

Review “Foundational Mathematics’ Skills of Physics” Packet (Page 1 & 2) with answer guide in the back of the class

Introduction to Insulators and conductors

Begin Electrostatics Lab


How do we compare and contrast the basic properties of an insulator and a conductor?What are characteristics and classification(s) of

electrically . . .conductive atoms?insulative atoms?semi-conductive atoms?conductive compounds?insulative compounds?semi-conductive compounds?

How do we compare and contrast the basic properties of an insulator and a conductor?What are characteristics and classification(s) of

electrically . . .conductive atoms?insulative atoms?semi-conductive atoms?conductive compounds?insulative compounds?semi-conductive compounds?

21.3 Insulators and Conductors

Conductor:

Charge flows freely

Metals

Insulator:

Almost no charge flows

Most other materials

Some materials are semiconductors.

Why are certain atoms conductors and other insulators?

Why are certain atoms conductors and other insulators?

Recall on the periodic table that there are elements that do not react known as the Noble Gases. This is because their valence or outer energy levels contain 8 electrons (†Helium only has 2 because it has only 1 energy level)

If possible other atoms on the periodic table will try to gain or lose electrons to acquire the same electron configurations as the Noble Gases.

Recall on the periodic table that there are elements that do not react known as the Noble Gases. This is because their valence or outer energy levels contain 8 electrons (†Helium only has 2 because it has only 1 energy level)

If possible other atoms on the periodic table will try to gain or lose electrons to acquire the same electron configurations as the Noble Gases.

A Conductor or an Insulator?A Conductor or an Insulator?

Are the following elements conductors or insulators? Justify your answer.SodiumChlorineOxygenPotassiumMagnesiumAluminumSilicon

Are the following elements conductors or insulators? Justify your answer.SodiumChlorineOxygenPotassiumMagnesiumAluminumSilicon

Sodium is a conductor because it loses electrons easily.

Sodium is a conductor because it loses electrons easily.

- 1 e-NaNa+Neon’s Electron

Configuration


How do we describe and apply the concept of induced charge and electrostatic shielding?How do we qualitatively explain the process of

charging by induction?How does an electroscope detect charge?

How do we describe and apply the concept of induced charge and electrostatic shielding?How do we qualitatively explain the process of

charging by induction?How does an electroscope detect charge?

The fact that both attractive and repulsive forces exist shows that there must be two different types of charges.

In the presence of a charged object, a neutral object can polarize – the charges opposite to those on the charged object move closer to it, and the other charges move away.


21.4 Induced Charge; the Electroscope

Metal objects can be charged by conduction:


They can also be charged by induction:

What does it mean to be “grounded“?


You must stay in the house for a week.You have lost your privilegesYou are in real trouble young man

Or

You are firm in your belief of high morality.

You must stay in the house for a week.You have lost your privilegesYou are in real trouble young man

Or

You are firm in your belief of high morality.



An object is said to be “grounded” or “earthed” when it is connected to a conducting wire or pipe leading into the ground.

Because the Earth is so large and can conduct electricity, it can easily accept or give up electrons. It is essentially a large reservoir or sink hole for (negative) electric charge (aka. electrons).

An object is said to be “grounded” or “earthed” when it is connected to a conducting wire or pipe leading into the ground.

Because the Earth is so large and can conduct electricity, it can easily accept or give up electrons. It is essentially a large reservoir or sink hole for (negative) electric charge (aka. electrons).

What would happen if . . .What would happen if . . .

a negatively-charged object were allowed to touch a ...metal faucet that was connected to ground

and the pipe were chopped off with a super axe hacker . . .before the negatively-charged object was

removedafter the negatively-charged object was removed

a negatively-charged object were allowed to touch a ...metal faucet that was connected to ground




a metal faucet that was connected to ground and the pipe were chopped off with a super axe hacker and a negatively-charged object were allowed to touch it . . .and the negatively-charged object were

then removed.

a metal faucet that was connected to ground and the pipe were chopped off with a super axe hacker and a negatively-charged object were allowed to touch it . . .and the negatively-charged object were

then removed.


a negatively-charged object were brought near a ...metal faucet that was connected to ground



a negatively-charged object were brought near a ...metal faucet that was connected to ground




a metal faucet that was connected to ground and the pipe were chopped off with a super axe hacker and a negatively-charged object were brought near it. . .and the negatively-charged object were

then removed.

a metal faucet that was connected to ground and the pipe were chopped off with a super axe hacker and a negatively-charged object were brought near it. . .and the negatively-charged object were

then removed.


a positively-charged object were allowed to touch a ...metal faucet that was connected to ground

and the pipe were chopped off with a super axe hacker . . .before the positively-charged object was removedafter the positively-charged object was removed

a positively-charged object were allowed to touch a ...metal faucet that was connected to ground



a metal faucet that was connected to ground and the pipe were chopped off with a super axe hacker and a positively-charged object were allowed to touch it . . .and the positively-charged object were then

removed.

a metal faucet that was connected to ground and the pipe were chopped off with a super axe hacker and a positively-charged object were allowed to touch it . . .and the positively-charged object were then

removed.


a positively-charged object were brought near a ...metal faucet that was connected to ground


a positively-charged object were brought near a ...metal faucet that was connected to ground



a metal faucet that was connected to ground and the pipe were chopped off with a super axe hacker and a positively-charged object were brought near it. . .and the positively-charged object were then

removed.

a metal faucet that was connected to ground and the pipe were chopped off with a super axe hacker and a positively-charged object were brought near it. . .and the positively-charged object were then

removed.


a negatively-charged piece of plastic were allowed to touch a ...metal faucet that was connected to ground

and the pipe were chopped off with a super axe hacker . . .before the negatively-charged piece of plastic

was removedafter the negatively-charged piece of plastic was

removed

a negatively-charged piece of plastic were allowed to touch a ...metal faucet that was connected to ground

and the pipe were chopped off with a super axe hacker . . .before the negatively-charged piece of plastic

was removedafter the negatively-charged piece of plastic was

removed


a positively-charged glass rod were allowed to touch a ...metal faucet that was connected to ground

and the pipe were chopped off with a super axe hacker . . .before the positively-charged glass rod was

removedafter the positively-charged glass rod was

removed

a positively-charged glass rod were allowed to touch a ...metal faucet that was connected to ground

and the pipe were chopped off with a super axe hacker . . .before the positively-charged glass rod was

removedafter the positively-charged glass rod was

removed

Electrostatics Lab #1Electrostatics Lab #1

5 Charge StationsDensity of Water

Graph: mass vs. volumeCalculate the slope

Water droplet/ml#of water droplets on pennyAvogadro’s number

5 Charge StationsDensity of Water

Graph: mass vs. volumeCalculate the slope

Water droplet/ml#of water droplets on pennyAvogadro’s number

SummarySummary

Identify two differences between insulators and conductors


(Page 13 & 14)

Identify two differences between insulators and conductors


(Page 13 & 14)

Monday (Day 4)Monday (Day 4)

Warm-UpWarm-Up

Mon, Jan 26 Identify the charges on the

Amber rodFurGlass RodSilk

Have you logged onto webassign.net? Place your homework on my desk:

“Foundational Mathematics’ Skills of Physics” Packet (Page 13 & 14)

Mon, Jan 26 Identify the charges on the

Amber rodFurGlass RodSilk








of Superposition?





of Superposition?



Electric Charge


Electric Charge






11

26 3 11 16 16 21

213

147 4 12 17 17 8

322

238 5 13 18 18 9

424†12

9 6 14 19 19 10

5 15 10 7 15 20 20 11


AgendaAgenda

Review “Foundational Mathematics’ Skills of Physics” Packet (Page 13 & 14) with answer guide in the back of the class.

Discuss induction in insulators and electroscopes Complete Electrostatics Lab #1 & 2

Review “Foundational Mathematics’ Skills of Physics” Packet (Page 13 & 14) with answer guide in the back of the class.

Discuss induction in insulators and electroscopes Complete Electrostatics Lab #1 & 2


Nonconductors won’t become charged by conduction or induction, but will experience charge separation:

Electron Cloud PolarizationElectron Cloud Polarization

Similar to the Temporary Dipole in I2

Similar to the Temporary Dipole in I2

21-4 Induced Charge

Conductors can be charged by induction:


The electroscope can be used for detecting charge:

21.4 Induced Charge; the ElectroscopeThe electroscope can be charged either by conduction or by induction.


The charged electroscope can then be used to determine the sign of an unknown charge.

21-4 The ElectroscopeThe electroscope is a device that detects the presence of excess free charge on an object. This can be done in two ways:

First, when a charged rod transfers charge directly to the electroscope, that charge spreads uniformly over its metal surfaces. The leaf and stem then have same-sign charges, and repel.

Second, when a charged rod is brought near, but not touching, the electroscope, it attracts opposite charges. The like charges tend to move away from the rod; once again the stem and leaf have same-sign charges, and repel.

21-4 The Electroscope

SummarySummary

What happens to the electrons in an insulator during the process of “charging by” induction?


(Page 22 - 23)Electrostatics Lab #1: Lab Report (Due in 6 classes)

What happens to the electrons in an insulator during the process of “charging by” induction?


(Page 22 - 23)Electrostatics Lab #1: Lab Report (Due in 6 classes)

Tuesday (Day 5)

Tuesday (Day 5)


Warm-UpWarm-Up

Tues, Jan 27 Complete Graphic Organizers for Sections 21-1 to 21-2



Future assignments:Electrostatics Lab #1 Packet and Conclusion

Questions (Due in 5 classes)Electrostatics Lab #2: Lab Report (Due in 5 classes)

Tues, Jan 27 Complete Graphic Organizers for Sections 21-1 to 21-2










of Superposition?





of Superposition?



Electric Charge


Electric Charge






11

26 3 11 16 16 21

213

147 4 12 17 17 8

322

238 5 13 18 18 9

424†12

9 6 14 19 19 10

5 15 10 7 15 20 20 11


AgendaAgenda

Review “Foundational Mathematics’ Skills of Physics” Packet (Page 22 & 23) with answer guide.

Discuss the quantized charge of electrons and protons Complete Electrostatic Labs #1 & 2


Discuss the quantized charge of electrons and protons Complete Electrostatic Labs #1 & 2


How do we describe and apply Coulomb’s Law and the Principle of Superposition?How do we compare and contrast Coulomb’s

Law and the Universal Law of Gravitation? How do we use Coulomb’s Law and the

principle of superposition to determine the force that acts between point charges?




21.5 Coulomb’s Law

Charge on the negative electron and positive proton is:

The basic unit of charge is the Coulomb, C. Electric charge is quantized in whole number multiples of the electron charge.

Q =ne(where n=1, 2, 3 , . . .)

e =m1.602 x 10−19 C

SummarySummary

From Electrostatics Lab #2: What is the total positive charge of water (in Coulombs)?

HW (Place in your agenda): “Foundational Mathematics’ Skills of Physics” Packet (Page

24) Web Assign Problems #1 & 2



From Electrostatics Lab #2: What is the total positive charge of water (in Coulombs)?

HW (Place in your agenda): “Foundational Mathematics’ Skills of Physics” Packet (Page

24) Web Assign Problems #1 & 2



Wednesday (Day 6)

Wednesday (Day 6)

School closed due to inclement weather

School closed due to inclement weather

Thursday(Day 6)

Thursday(Day 6)

Two Hour Delay due to inclement weather

Two Hour Delay due to inclement weather

Warm-UpWarm-Up

Thurs, Jan 29 Complete Graphic Organizers for Sections 21-3 to 21-4

For § 21-4: Identify how the process of charging by friction, induction, and conduction applies to:Walking across the carpet and touching a doorknobA Van de Graaff Generator Lightning

Place your homework on my desk:“Foundational Mathematics’ Skills of Physics” Packet (Page 24)Web Assign Problems #1 & 2

Thurs, Jan 29 Complete Graphic Organizers for Sections 21-3 to 21-4

For § 21-4: Identify how the process of charging by friction, induction, and conduction applies to:Walking across the carpet and touching a doorknobA Van de Graaff Generator Lightning

Place your homework on my desk:“Foundational Mathematics’ Skills of Physics” Packet (Page 24)Web Assign Problems #1 & 2

Warm-UpWarm-Up

Thurs, Jan 29

Future assignments:Electrostatics Lab #1 Packet and Conclusion Questions

(Due in 4 classes)Electrostatics Lab #2: Lab Report (Due in 4 classes)

Teacher Assignment:Acquire an IBM-Compatible computer for EM Field

Thurs, Jan 29

Future assignments:Electrostatics Lab #1 Packet and Conclusion Questions

(Due in 4 classes)Electrostatics Lab #2: Lab Report (Due in 4 classes)

Teacher Assignment:Acquire an IBM-Compatible computer for EM Field



HOW DO WE DESCRIBE THE NATURE OF ELECTROSTATICS AND APPLY IT TO VARIOUS SITUATIONS?How do we describe and apply the concept of electric field?How do we describe and apply Coulomb’s Law and the Principle

of Superposition?



of Superposition?



Electric Charge


Electric Charge






11

26 3 11 16 16 21

213

147 4 12 17 17 8

322

238 5 13 18 18 9

424†12

9 6 14 19 19 10

5 15 10 7 15 20 20 11


AgendaAgenda

Review “Foundational Mathematics’ Skills of Physics” Packet (Page 24) with answer guide.

Review select Electrostatic Lab #1 & 2 Results Discuss Coulomb’s Law, Newton’s Law of Gravitation,

and the Superposition Principle Apply Coulomb’s Law Begin The Four Circles Graphic Organizer

Review “Foundational Mathematics’ Skills of Physics” Packet (Page 24) with answer guide.

Review select Electrostatic Lab #1 & 2 Results Discuss Coulomb’s Law, Newton’s Law of Gravitation,

and the Superposition Principle Apply Coulomb’s Law Begin The Four Circles Graphic Organizer









Experiment shows that the electric force between two charges is proportional to the product of the charges and inversely proportional to the distance between them.

How do we compare and contrast Coulomb’s Law and the Universal Law of Gravitation?

6.1 Newton’s Law of Gravitation

Experiment shows that the gravitational force between two masses is proportional to the product of the masses and inversely proportional to the distance between them.



Coulomb’s law:

This equation gives the magnitude of the force.



Newton’s Law of Gravitation:

This equation gives the magnitude of the force.

F =−Gm1m2

r2


21.5 Coulomb’s LawThe electric force is along the line connecting the

charges, and is attractive if the charges are opposite, and repulsive if they are the same.


6.1 Newton’s Law of GravitationThe gravitational force is along the line

connecting the masses and is always attractive regardless of the size either mass.



Unit of charge: coulomb, C

The proportionality constant in Coulomb’s law is then:

Charges produced by rubbing are typically around a microcoulomb:



Unit of charge: coulomb, C

The proportionality constant in Coulomb’s law is then:

Charges produced by rubbing are typically around a microcoulomb:



Unit of mass: kilogram, kg

The proportionality constant in Newton’s law is:

NOTE: The Gravitational constant is significantly less than the electrostatic constant . . . Yes, we are going to calculate this difference.


SummarySummary

After comparing the force constants for electrostatics and gravity, identify which Force is stronger.

HW (Place in your agenda): †“Foundational Mathematics’ Skills of Physics” Packet (Page 12)Web Assign Problems #3

Future assignments:Electrostatics Lab #1 Packet and Conclusion Questions (Due in 4

classes)Electrostatics Lab #2: Lab Report (Due in 4 classes)


HW (Place in your agenda): †“Foundational Mathematics’ Skills of Physics” Packet (Page 12)Web Assign Problems #3




Friday (Day 7)Friday (Day 7)

Warm-UpWarm-Up

Fri, Jan 30 Begin Graphic Organizer for Sections 21-5

Place your homework on my desk: †“Foundational Mathematics’ Skills of Physics” Packet (Page 12)



Fri, Jan 30 Begin Graphic Organizer for Sections 21-5

Place your homework on my desk: †“Foundational Mathematics’ Skills of Physics” Packet (Page 12)






of Superposition?



of Superposition?



Electric Charge


Electric Charge






11

26 3 11 16 16 21

213

147 4 12 17 17 8

322

238 5 13 18 18 9

424†12

9 6 14 19 19 10

5 15 10 7 15 20 20 11


AgendaAgenda

†Review “Foundational Mathematics’ Skills of Physics” Packet (Page 12) with answer guide.

Review select Electrostatic Lab #1 & 2 Results Coulomb’s Law & Vectors Applications of Coulomb’s Law


Review select Electrostatic Lab #1 & 2 Results Coulomb’s Law & Vectors Applications of Coulomb’s Law









The proportionality constant k can also be written in terms of , the permittivity of free space:

How do we use Coulomb’s Law and the principle of superposition to determine the force that acts between point charges?

21.5 Coulomb’s LawCoulomb’s law strictly applies only to point charges.

Superposition: for multiple point charges, the forces on each charge from every other charge can be calculated and then added as vectors.


21.5 Solving Problems Involving Coulomb’s Law and Vectors

The net force on a charge is the vector sum of all the forces acting on it.


21.5 Solving Problems Involving Coulomb’s Law and Vectors

Vector addition review:


3 Dimensional Axes & Unit Vector Notation

3 Dimensional Axes & Unit Vector Notation


Steps for Solving Coulomb’s Law Problems:

Determine the direction of the force


Determine the direction of the forceDetermine if your force vectors will

represent all forces as repulsive. (NOTE: Since the CORRECT direction of the force may NOT have been established, the values of the charges, q, must be entered as POSITIVE or NEGATIVE into Coulomb’s Law. This is similar to substituting a=-9.8 m/s2 into a kinematic equations): GENERAL CASE

OREstablish the direction of the force as repulsive or

attractive. (NOTE: Since the direction of the force is now established in the correct direction, all charges, q, will be POSITIVE values when entered into Coulomb’s Law. This is similar to establishing a=-g in the 2-D kinematic equations): SPECIFIC CASE

Determine if your force vectors will represent all forces as repulsive. (NOTE: Since the

CORRECT direction of the force may NOT have been established, the values of the charges, q, must be entered as POSITIVE or NEGATIVE into Coulomb’s Law. This is similar to substituting a=-9.8 m/s2 into a kinematic equations): GENERAL CASE

OREstablish the direction of the force as repulsive or

attractive. (NOTE: Since the direction of the force is now established in the correct direction, all charges, q, will be POSITIVE values when entered into Coulomb’s Law. This is similar to establishing a=-g in the 2-D kinematic equations): SPECIFIC CASE



Problem Solving


Problem SolvingResolve the force vectorsSum up the force vectors in the x, y, and z

directionsUse Pythagorean Theorem to determine the

magnitude of the resultant force vectorUse SOH CAH TOA to determine the direction

of the resultant force vector

Sounds simple, yah?

Resolve the force vectorsSum up the force vectors in the x, y, and z

directionsUse Pythagorean Theorem to determine the

magnitude of the resultant force vectorUse SOH CAH TOA to determine the direction

of the resultant force vector

Sounds simple, yah?


Applying Coulomb’s LawApplying Coulomb’s Law

Three charge are placed are a fixed distance apart shown on the following slide. The charge on Q2 is +50 C located at the origin.

The charge on Q1 is -86 C located at 52 cm to the right of Q2.

The charge on Q3 is +65 C located at 30 cm above Q2.

Calculate the net electrostatic force on charge Q3 due to charges Q1 and Q2.

Three charge are placed are a fixed distance apart shown on the following slide. The charge on Q2 is +50 C located at the origin.



Calculate the net electrostatic force on charge Q3 due to charges Q1 and Q2.


Applying Coulomb’s LawApplying Coulomb’s Law52 cmQ2 = +50 CQ3 = +50 CQ1 = -86 C30o







Relationship between force and distance

Relationship between force and distance

How would the force change IF the distance were doubled?

How would the force change IF the distance were doubled?

FDistance 1 ∝ 1r2

FDistance 2 ∝ 12r( )2

=14r2

FDistance 2

FDistance 1

∝14r2

1r2

=r2

4r2 =14


SummarySummary


HW (Place in your agenda): “Foundational Mathematics’ Skills of Physics” Packet (Page 15) Web Assign Problems #3

Future assignments: Electrostatics Lab #1 Packet and Conclusion Questions (Due in 3 classes) Electrostatics Lab #2: Lab Report (Due in 3 classes)





Monday (Day 8)Monday (Day 8)

Warm-UpWarm-UpMon, Feb 2

How many total moles of electrons would have to be removed from the earth and the moon to cancel out the attractive gravitational force between them?

Place your homework on my desk: “Foundational Mathematics’ Skills of Physics” Packet (Page 12 & 15) Graphic Organizers for Sections 21-1 to 21-4

Have you complete WebAssign Problems 21.1 - 21.3?


Mon, Feb 2 How many total moles of electrons would have to be removed from

the earth and the moon to cancel out the attractive gravitational force between them?

Place your homework on my desk: “Foundational Mathematics’ Skills of Physics” Packet (Page 12 & 15) Graphic Organizers for Sections 21-1 to 21-4

Have you complete WebAssign Problems 21.1 - 21.3?





of Superposition?



of Superposition?



Electric Charge


Electric Charge






11

26 3 11 16 16 21

213

147 4 12 17 17 8

322

238 5 13 18 18 9

424†12

9 6 14 19 19 10

5 15 10 7 15 20 20 11


AgendaAgenda


Butter Gun Applications of Coulomb’s Law Coulomb’s Law Lab


Butter Gun Applications of Coulomb’s Law Coulomb’s Law Lab








Reviewing the warm-up: Just a thought . . .

Reviewing the warm-up: Just a thought . . .



592 615 508 moles of electrons each1 185 231 015 moles of electrons total


The Butter GunThe Butter Gun



Applying Coulomb’s LawApplication #2


(III) Three charge are placed are a fixed distance apart shown on the following slide. The charge on Q2 is +50 C located at the origin.



Qualitatively identify the possible locations of a POSITIVE 4th charge, Q4, of +1 C so it does not feel a force due charges Q1, Q2, and Q3 using force diagrams.

Where do you think it would be if the 4th charge were NEGATIVE?

(III) Three charge are placed are a fixed distance apart shown on the following slide. The charge on Q2 is +50 C located at the origin.



Qualitatively identify the possible locations of a POSITIVE 4th charge, Q4, of +1 C so it does not feel a force due charges Q1, Q2, and Q3 using force diagrams.

Where do you think it would be if the 4th charge were NEGATIVE?










(III) IF two of the three charge are placed are a fixed distance apart shown on the following slide. The charge on Q2 is +50 C located at the origin. The charge on Q1 is -86 C located at 52 cm to the right of Q2. The charge on Q3 is +65 C located at 30 cm above Q2.

Identify the locations from the origin of a POSITIVE 4th charge, Q4, of +1 C so it does not feel a force due to chargesQ1, and Q2.Q2 and Q3.






SummarySummary

Coulomb’s Law Application #3: Determine the location(s) along the x-axis and y-axis for a positive particle to feel a Fnet = 0 N.

HW (Place in your agenda): “Foundational Mathematics’ Skills of Physics” Packet (Page 3)Coulomb’s Law Application #3



Coulomb’s Law Application #3: Determine the location(s) along the x-axis and y-axis for a positive particle to feel a Fnet = 0 N.

HW (Place in your agenda): “Foundational Mathematics’ Skills of Physics” Packet (Page 3)Coulomb’s Law Application #3




Tuesday (Day 9)

Tuesday (Day 9)

Warm-UpWarm-Up

Tues, Feb 3 Continue Graphic Organizer for Section 21-5

Place your homework on my desk:“Foundational Mathematics’ Skills of Physics” Packet (Page 3)Graphic Organizers?

Have you complete WebAssign Problems: 21.1 - 21.4? Future assignments:

Electrostatics Lab #1 Packet and Conclusion Questions (Due in 1 class)

Electrostatics Lab #2: Lab Report (Due in 1 class)

Tues, Feb 3 Continue Graphic Organizer for Section 21-5

Place your homework on my desk:“Foundational Mathematics’ Skills of Physics” Packet (Page 3)Graphic Organizers?


Electrostatics Lab #1 Packet and Conclusion Questions (Due in 1 class)

Electrostatics Lab #2: Lab Report (Due in 1 class)




of Superposition?



of Superposition?



Electric Charge


Electric Charge






11

26 3 11 16 16 21

213

147 4 12 17 17 8

322

238 5 13 18 18 9

424†12

9 6 14 19 19 10

5 15 10 7 15 20 20 11


AgendaAgenda


Complete Coulomb’s Law Lab Complete Web Assign Problem #4


Complete Coulomb’s Law Lab Complete Web Assign Problem #4

SummarySummary

Write down the answer to question 7 on Electrostatics Lab #3 (What happens just before the balls touch?).


Future assignments: Electrostatics Lab #1 Packet and Conclusion Questions (Due tomorrow) Electrostatics Lab #2: Lab Report (Postponed Due 1 class) Electrostatics Lab #3: Lab Report (Due in 5 classes)

Write down the answer to question 7 on Electrostatics Lab #3 (What happens just before the balls touch?).


Future assignments: Electrostatics Lab #1 Packet and Conclusion Questions (Due tomorrow) Electrostatics Lab #2: Lab Report (Postponed Due 1 class) Electrostatics Lab #3: Lab Report (Due in 5 classes)


Wednesday (Day 10)

Wednesday (Day 10)

Warm-UpWarm-Up

Wed, Feb 4 Finish Graphic Organizer for Section 21-5

Place your homework on my desk:“Foundational Mathematics’ Skills of Physics” Packet (Page 4)Electrostatics Lab #1 Packet and Conclusion Questions


Electrostatics Lab #2: Lab Report (POSTPONED - Due in 1 class)Electrostatics Lab #3: Lab Report (Due in 4 classes)

Wed, Feb 4 Finish Graphic Organizer for Section 21-5

Place your homework on my desk:“Foundational Mathematics’ Skills of Physics” Packet (Page 4)Electrostatics Lab #1 Packet and Conclusion Questions


Electrostatics Lab #2: Lab Report (POSTPONED - Due in 1 class)Electrostatics Lab #3: Lab Report (Due in 4 classes)




of Superposition?



of Superposition?



Electric Charge


Electric Charge






11

26 3 11 16 16 21

213

147 4 12 17 17 8

322

238 5 13 18 18 9

424†12

9 6 14 19 19 10

5 15 10 7 15 20 20 11


AgendaAgenda


From “Foundational Mathematics’ Skills of Physics” (Page 24): 3D Angles, Trigonometry, and xyz-Components

Complete Coulomb’s Law Lab Begin The Four Circles Graphic Organizer Complete Web Assign Problem #4


From “Foundational Mathematics’ Skills of Physics” (Page 24): 3D Angles, Trigonometry, and xyz-Components

Complete Coulomb’s Law Lab Begin The Four Circles Graphic Organizer Complete Web Assign Problem #4










3D Angles, Trigonometry, and xyz-Components

3D Angles, Trigonometry, and xyz-Components

x

y

z

φ

θ

ll

l

αx

y

z

φ

θ

ll

l

α

Fx =F cosα cosφ

=FFxz

FFx

Fxz

Fy =F sinα

=FFy

FFx =F cosα sinφ

=FFyz

FFz

Fxz

SummarySummary

(Assignment from 2 classes ago) Write down the locations for Coulomb’s Law Application Question #3.


Future assignments: Electrostatics Lab #2: Lab Report (Due tomorrow) Electrostatics Lab #3: Lab Report (Due in 4 classes)

(Assignment from 2 classes ago) Write down the locations for Coulomb’s Law Application Question #3.


Future assignments: Electrostatics Lab #2: Lab Report (Due tomorrow) Electrostatics Lab #3: Lab Report (Due in 4 classes)


Documents

Physics II: Electricity & Magnetism Introduction, Sections 21.1 to 21.5