physics ii: electricity & magnetism

Physics II:Electricity & Magnetism

Physics II:Electricity & Magnetism

Binomial Expansions, Riemann Sums, Sections 21.6

& 21.8

Binomial Expansions, Riemann Sums, Sections 21.6

& 21.8

Friday (Day 12)Friday

(Day 12)

Warm-UpWarm-Up

Fri, Feb 6 Calculate the velocity of the electron moving around the hydrogen nucleus (r

= 0.53 x 10-10 m)

Place your homework on my desk: “Foundational Mathematics’ Skills of Physics” Packet (Page 6) Derivative Practice

For future assignments - check online at www.plutonium-239.com

Fri, Feb 6 Calculate the velocity of the electron moving around the hydrogen nucleus (r

= 0.53 x 10-10 m)

Place your homework on my desk: “Foundational Mathematics’ Skills of Physics” Packet (Page 6) Derivative Practice

For future assignments - check online at www.plutonium-239.com

Warm-Up ReviewWarm-Up Review

Calculate the velocity of the electron moving around the hydrogen nucleus (r = 0.53 x 10-10 m)

Calculate the velocity of the electron moving around the hydrogen nucleus (r = 0.53 x 10-10 m)

Essential Question(s)Essential Question(s)

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 describe and apply Coulomb’s Law and the Principle

of Superposition?



of Superposition?

VocabularyVocabulary Static Electricity Electric Charge Positive / Negative Attraction / Repulsion Charging / Discharging Friction Induction Conduction Law of Conservation of Electric

Charge Non-polar Molecules

Static Electricity Electric Charge Positive / Negative Attraction / Repulsion Charging / Discharging Friction Induction Conduction Law of Conservation of Electric


Polar Molecules Ion Ionic Compounds Force Derivative Integration (Integrals) Test Charge Electric Field Field Lines Electric Dipole Dipole Moment


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

Review “Foundational Mathematics’ Skills of Physics” Packet (Page 6) with answer guide.

Review Derivative Practice INTEGRAL PROOF USING RIEMANN SUMS Integral Practice

MONDAY: Discuss Electric Fields & Gravitational Field Apply Electric Fields Continue with The Four Circles Graphic Organizer


Review Derivative Practice INTEGRAL PROOF USING RIEMANN SUMS Integral Practice

MONDAY: Discuss Electric Fields & Gravitational Field Apply Electric Fields Continue with The Four Circles Graphic Organizer

Topic #1: Determine the slope at point A for f(x)=xn


y = 1/2 x




y = 1/4 x2


SummarySummary

Identify one section that in the Integral Proof using Riemann Sums that was confusing?

HW (Place in your agenda): “Foundational Mathematics’ Skills of Physics” Packet (Page 7) Go through the Riemann sum derivation - determine what you do not

understand. Integral Practice

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

Identify one section that in the Integral Proof using Riemann Sums that was confusing?

HW (Place in your agenda): “Foundational Mathematics’ Skills of Physics” Packet (Page 7) Go through the Riemann sum derivation - determine what you do not

understand. Integral Practice


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

Monday (Day 13)Monday (Day 13)

Warm-UpWarm-UpMon, Feb 9

1. If I measured the distance of each step I took and summed them all together, what would I have calculated?

2. If I was driving in a car on the turnpike at a constant speed and I multiplied my speed by the time I was traveling, what would I have calculated?

3. Now make it more complex, what if my speed was slowly changing and I1. Wrote down my velocity and the amount of time I was traveling at that velocity;2. Multiplied those two numbers together;3. Added those new numbers together; What would I have calculated?

Place your homework on my desk: “Foundational Mathematics’ Skills of Physics” Packet (Page 7) Integral Practice

1. For future assignments - check online at www.plutonium-239.com

Mon, Feb 91. If I measured the distance of each step I took and summed them all together, what

would I have calculated?2. If I was driving in a car on the turnpike at a constant speed and I multiplied my speed

by the time I was traveling, what would I have calculated?3. Now make it more complex, what if my speed was slowly changing and I

1. Wrote down my velocity and the amount of time I was traveling at that velocity;2. Multiplied those two numbers together;3. Added those new numbers together; What would I have calculated?

Place your homework on my desk: “Foundational Mathematics’ Skills of Physics” Packet (Page 7) Integral Practice

1. For future assignments - check online at www.plutonium-239.com

Warm-UpWarm-Up

Mon, Feb 91. If I measured the distance of each step I took and summed them all

together, what would I have calculated?2. If I was driving in a car on the turnpike at a constant speed and I

multiplied my speed by the time I was traveling, what would I have calculated?

3. Now make it more complex, what if my speed was slowly changing and I

1. Wrote down my velocity and the amount of time I was traveling at that velocity;

2. Multiplied those two numbers together;3. Added those new numbers together; What would I have calculated?

Mon, Feb 91. If I measured the distance of each step I took and summed them all

together, what would I have calculated?2. If I was driving in a car on the turnpike at a constant speed and I

multiplied my speed by the time I was traveling, what would I have calculated?

3. Now make it more complex, what if my speed was slowly changing and I

1. Wrote down my velocity and the amount of time I was traveling at that velocity;

2. Multiplied those two numbers together;3. Added those new numbers together; What would I have calculated?

Essential Question(s)Essential Question(s)



of Superposition?



of Superposition?

VocabularyVocabulary Static Electricity Electric Charge Positive / Negative Attraction / Repulsion Charging / Discharging Friction Induction Conduction Law of Conservation of Electric


Static Electricity Electric Charge Positive / Negative Attraction / Repulsion Charging / Discharging Friction Induction Conduction Law of Conservation of Electric






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


Complete the Integral Proof using Riemann Sums Review Integral Practice Discuss

Electric Fields Gravitational Field Field Lines

Continue with The Four Circles Graphic Organizer Apply Electric Fields


Complete the Integral Proof using Riemann Sums Review Integral Practice Discuss

Electric Fields Gravitational Field Field Lines

Continue with The Four Circles Graphic Organizer Apply Electric Fields

Riemann Sums ProofRiemann Sums Proof

ADD RIEMANN SUMS PROOF HEREADD RIEMANN SUMS PROOF HERE

Riemann SumsRiemann Sums

Riemann Sums Related to RealityRiemann Sums Related to Reality

Big Picture Ideas and RelationshipsBig Picture Ideas and Relationships

If F(x) is written as x(t) (aka. Displacement as a function of time)

Then slope of the graph, F’(x), can be written as x’(t) (aka v(t), the velocity as a function of time)

And F(b) - F(a) is the really the just the xfinal - xinitial.

This is also equal to the summation of all velocity x time calculations [f(ci)(xi-xi-1)] or rewritten as [v(ci)(ti-ti-1)]

If F(x) is written as x(t) (aka. Displacement as a function of time)

Then slope of the graph, F’(x), can be written as x’(t) (aka v(t), the velocity as a function of time)

And F(b) - F(a) is the really the just the xfinal - xinitial.

This is also equal to the summation of all velocity x time calculations [f(ci)(xi-xi-1)] or rewritten as [v(ci)(ti-ti-1)]

The graph of y(x)Referred to as F(x) [or x(t)]

The graph of y(x)Referred to as F(x) [or x(t)]

x(a)

x(b)

x ti−1( )

x(ti )ti −ti−1

x(ti )−x ti−1( )ti −ti−1

′x (ci ) = v(ci )

Δt Δt

The graph of y’(x);Called F’ (x); [or x’ (t)]

The graph of y’(x);Called F’ (x); [or x’ (t)]

The graph of F’(x) is renamed f(x); [or x’ (t) is renamed v(t)]The graph of F’(x) is renamed f(x); [or x’ (t) is renamed v(t)]

Riemann Sum with only 1 approximation (Δt: large)Riemann Sum with only 1 approximation (Δt: large)

tt

x

x(a)

x(b)

x ti−1( )

x(ti )

ti −ti−1


′x (ci ) = v(ci )

x(ci ) only a reference point; not the "height"

Riemann Sum with only 2 approximations (Δt: still large)

Riemann Sum with only 2 approximations (Δt: still large)

t

x

x(a)

x(b)

x ti−1( )

x(ti )

ti −ti−1


′x (ci ) = v(ci )

Riemann Sum with 9 approximations (Δt: medium)

Riemann Sum with 9 approximations (Δt: medium)

t

x

x(a)

x(b)

x ti−1( )

x(ti )

ti −ti−1


′x (ci ) = v(ci )

Δt

Δt

Riemann Sum with 17 approximations (Δt: small)

Riemann Sum with 17 approximations (Δt: small)

t

x

x(a)

x(b)

x ti−1( )x(ti )

ti −ti−1


′x (ci ) = v(ci )

Δt

Riemann Sum with only 33 approximations (Δt: smaller)Riemann Sum with only 33 approximations (Δt: smaller)

t

x


Confusing Points:x(ci) is only a point of reference, not the “height” to which

the Δt is multiplied to get the area under the curve. In fact, it is the area under the v(t) graph that we are trying

to find in order to determine the total displacement.

Confusing Points:x(ci) is only a point of reference, not the “height” to which

the Δt is multiplied to get the area under the curve. In fact, it is the area under the v(t) graph that we are trying

to find in order to determine the total displacement.


As Δt decreases, your approximations become more accurate.

Note: Summing up all of the “slope of x vs t times Δt” (aka. “velocity x time”) calculations will equal the

total displacement (aka. The final position minus the starting position).

As Δt decreases, your approximations become more accurate.

Note: Summing up all of the “slope of x vs t times Δt” (aka. “velocity x time”) calculations will equal the

total displacement (aka. The final position minus the starting position).

Section 21.6Section 21.6

How do we describe and apply the concept of electric field?How do we define electric fields in terms of the

force on a test charge?

How do we describe and apply the concept of electric field?How do we define electric fields in terms of the

force on a test charge?


How do we describe and apply Coulomb’s Law and the Principle of Superposition?How do we use Coulomb’s Law to describe the

electric field of a single point charge?How do we use vector addition to determine

the electric field produced by two or more point charges?

How do we describe and apply Coulomb’s Law and the Principle of Superposition?How do we use Coulomb’s Law to describe the

electric field of a single point charge?How do we use vector addition to determine

the electric field produced by two or more point charges?

21.6 The Electric Field

The electric field is the force on a small charge, divided by the charge:


For a point charge:


Force on a point charge in an electric field:

Superposition principle for electric fields:


Problem solving in electrostatics: electric forces and electric fields

1. Draw a diagram; show all charges, with signs, and electric fields and forces with directions

2. Calculate forces using Coulomb’s law

3. Add forces vectorially to get result


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 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?

21.8 Field Lines

The electric field can be represented by field lines. These lines start on a positive charge and end on a negative charge.

Electric Field created by a spherically charged objectElectric Field created by a spherically charged object

21.8 Field Lines

The number of field lines starting (ending) on a positive (negative) charge is proportional to the magnitude of the charge.

The electric field is stronger where the field lines are closer together.

21.8 Field Lines

Electric dipole: two equal charges, opposite in sign:

21.8 Field Lines

Summary of field lines:

1. Field lines indicate the direction of the field; the field is tangent to the line.

2. The magnitude of the field is proportional to the density of the lines.

3. Field lines start on positive charges and end on negative charges; the number is proportional to the magnitude of the charge.

21.8 Field Lines

Summary of field lines:

4. Field lines never cross because the electric field cannot have two values for the same point.

EM Field uses color to represent the field strength (ie. Red is stronger; blue is weaker). Each charge below is ±10q. EM Field uses color to represent the field strength (ie. Red is stronger; blue is weaker). Each charge below is ±10q.

SummarySummary

Using Newton’s Second Law, what the formula for force?

HW (Place in your agenda): “Foundational Mathematics’ Skills of Physics” Packet (Page 16) Web Assign 21.5 - 21.7


Using Newton’s Second Law, what the formula for force?

HW (Place in your agenda): “Foundational Mathematics’ Skills of Physics” Packet (Page 16) Web Assign 21.5 - 21.7


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

physics ii: electricity & magnetism

Documents

constant speed

electric fieldscontinue

concept of electric

principle of superposition

electrostatics lab

riemann sum derivation

point charges

coulombs law