Physics 117 – Fall 2013 – Day by Day Schedule
Day 1 (Wednesday, August 21) ................................................................................................. 3
Day 2 (Friday, August 23th) ....................................................................................................... 4
Day 3 (Monday, August 26th)..................................................................................................... 5
Day 4 (Wednesday, August 28th) .............................................................................................. 6
Day 5 (Friday, August 30st)........................................................................................................ 7
Day 6 (Wednesday, Sept 4th) .................................................................................................... 8
Day 7 (Friday, Sept 6th) ............................................................................................................. 9
Day 8 (Monday, Sept 9th) .........................................................................................................10
Day 9 (Wednesday, Sept 11th) ..................................................................................................11
Day 10 (Friday, Sept 13th) .........................................................................................................12
Day 11 (Monday, Sept 16th) ......................................................................................................13
Day 12 (Wednesday, Sept 18th) ................................................................................................14
Day 13, (Friday, Sept 20th) ........................................................................................................15
Day 14, (Monday, Sept 23th) ....................................................................................................16
Day 15, (Wednesday, Sept 25th) ..............................................................................................17
Day 16, (Friday, Sept 27th) ........................................................................................................18
Day 17, (Monday, Sept 30th) .....................................................................................................19
Day 18, (Wednesday, Oct 2nd) .................................................................................................20
Day 19, (Friday, Oct 4th) ...........................................................................................................21
Day 20, (Monday, Oct 7th) .........................................................................................................22
Day 21, (Wednesday, Oct 9th) ...................................................................................................23
Day 22, (Friday, Oct 11th) ..........................................................................................................24
Day 23, (Monday, Oct 14th) .......................................................................................................25
Day 24, (Wednesday, Oct 16th) .................................................................................................26
Day 25, (Monday, Oct 21st) .......................................................................................................27
Day 26, (Wednesday, Oct 23rd) .................................................................................................28
Day 27, (Friday, Oct 25th) ..........................................................................................................29
Day 28, (Monday, Oct 28th) .......................................................................................................30
Day 29, (Wednesday, Oct 30th) .................................................................................................31
Day 30, (Friday, Nov 1st) ...........................................................................................................32
Day 31, (Monday, Nov 4th) ........................................................................................................33
Day 32, (Wednesday, Nov 6th) ..................................................................................................34
Day 33, (Friday, Nov 8th) ...........................................................................................................35
Day 34, (Monday, Nov 11th) ......................................................................................................36
Day 35, (Wednesday, Nov 13th) ................................................................................................37
Day 36, (Friday, Nov 15th) .........................................................................................................38
Day 37, (Monday, Nov 18th) ......................................................................................................39
Day 38, (Wednesday, Nov 20th) ................................................................................................40
Day 39, (Friday, Nov 22th) ........................................................................................................41
Day 40, (Monday, Nov 25th) ......................................................................................................42
Day 41, (Monday, Dec 2nd) ........................................................................................................43
Day 42, (Wednesday, Dec 4th) ..................................................................................................43
Day 1 (Wednesday, August 21)
Class meeting
1
Expected Time
Topics
General introduction to Electrostatics
Textbook sections
Chapter 21
Demos in lecture
Coke can rolling?
Lab
Electrostatics Investigations
60 minutes
OVERVIEW of course
50 minutes
Actual Time
Ponderables
Mini-lectures
Quiz
Simulations
Other
●
●
●
No warm-up questions to review
Introductions, overview of course, discussion of lab books
○ Need an overview of E&M and the course
○ Specifics about SCALEUP/collaborative group learning
■ Have everyone make name tags (we’ll add groups later)??
■ Bonus on exams for groups with good performance
■ Overview of ponderables
○ Lab book overview
■ Will be graded – frequency of spot checks
■ What to include
ElectroStatic Tape investigation (in labs folder)
○ Materials needed
■Tape
■String/thread
■Box of electrostatics stuff (fur, rods, etc.)
■Printout of worksheet
○
Encourage students to not overthink and work through – in an hour they should be able to make
their way at least to the start of part 3 on dipoles
○
Collect worksheets at end of class per group
Day 2 (Friday, August 23th)
Class meeting
2
Topics
Electrostatics
Textbook sections
Chapter 21
Expected Time
Actual Time
Demos in lecture
Lab
Ponderables
Coulomb force question
30 minutes
Mini-lectures
Coulomb’s Force and intro to E Fields
Triboelectric series/materials
15 minutes
10 minutes
CSEM and attitudinal survey
45 minutes
Quiz
Simulations
Other
●
●
Lecture – Coulombs Law
Ponderable (3 point charges on a triangle)
○ posted on Sakai
●
CSEM
○
○
○
○
○
introduce concept of ponderables group work – white board usage, skeptic, scribe and schemer
Introduce why these are important – participation credit only!
hand out green folders (check that they are all 117!)
Write survey monkey address on board for attitudinal survey (?)
Day 3 (Monday, August 26th)
Class meeting
3
Topics
Charge distributions and integrals
Textbook sections
Chapter 22
Expected Time
Actual Time
Demos in lecture
Lab
Ponderables
Lightning round
45 minutes
Mini-lectures
E-Fields (charge distributions)
15 minutes
Quiz
Simulations
Electric field hockey (time permitting)
Other
Announce Groups/contracts/name tags
Attitudinal survey (?)
Hands on E-Field worksheet
●
●
15 minutes
15 minutes
20 minutes
Post group assignments as students enter the room
○ have students exchange contact info and give example group contracts
○ time to make own contracts ??
○ Make name tags (use index cards in room)
Warm up review
○
A charge +q sits 1 cm from a second charge -3q. How
does the magnitude of the force the first charge (+q)
feels compare to the magnitude of the force the
second charge (-3q) feels?
■
■
■
■
It’s 2 times as large
It’s ⅓ as large
It’s the same magnitude
Not enough information
Newton’s Third Law
% Correct: 90
○
At a distance of one centimeter from an electron, the electric
field strength has a value E. At what distance is the electric
field strength equal to E/2?
■
■
■
■
3.2 cm
4.0 cm
2.0 cm
1.4 cm
Field strength is proportional to 1/r^2
% Correct: 96
●
●
●
E-field discussion
Hands on E Field worksheet (group based)
Lightning round ○ Just set up lots of different configurations - determine infinitesimal and how to set up integrals
○ Cover some of the book examples plus other configurations – don’t solve any integrals
○ Focus on how to find infinitesimals for charge distributions and setting up integrals
●
●
If there’s extra time – the Electric Field Hockey Phet simulation is a fun break today after all the integrals
Attitudinal survey (read the following to students)
■ The Physics and Astronomy Department is introducing changes to its introductory Physics courses
■
designed to improve student learning. Collecting information from students enrolled in these
courses is important to the evaluation of these efforts. Please take a few minutes to complete the
online survey at: https://www.surveymonkey.com/s/C952F9W
■ The survey is being administered by the Center for Faculty Excellence. No one affiliated with the
Physics and Astronomy Department, including your instructor, will have access to any identifying
information. The results of this survey will not, in any way, affect your grade for this course.
We appreciate your candid responses and your willingness to help us improve teaching and learning at Carolina.
Day 4 (Wednesday, August 28th)
Class meeting
4
Expected Time
Van de Graff Generator demo
15 minutes
Ponderables
E-field Ponderables
40 minutes
Mini-lectures
Dipoles
15 minutes
Actual Time
Topics
Textbook sections
Demos in lecture
Lab
Quiz
Simulations
Phet Hockey Challenge
Other
Gauss’s Law Tutorial
●
Warm up questions
○
A charged point particle is placed at the center of a
spherical Gaussian surface. The electric flux is changed
if
■
■
■
■
■
●
●
●
60 minutes
the sphere is replaced by a cube of the
same volume
Flux depends on enclosed charge.
% Correct: 85
○
The outer surface of the cardboard center of a
paper towel roll:
the sphere is replaced by a cube of
one-tenth the volume
■
■
the point charge is moved off center
(but still inside the original sphere)
■
the point charge is moved to just
outside the sphere
■
a second point charge is placed just
outside the sphere
is a possible Gaussian surface
cannot be a Gaussian surface because
it encloses no charge
cannot be a Gaussian surface since it
is an insulator
cannot be a Gaussian surface
because it is not a closed surface
○
E-field Ponderables (just two this time – telephone company and Duke Energy)
○ About 15-20 minutes to work on a question (each group chooses?)
○ 10 minutes per problem to present
Van de Graff Generator Demo (break up class between Tutorial work and quiz)
Phet hockey Challenge (Don’t let this activity go too long – it’s just a quick way to break up what we’re
doing)
○
○
○
One computer per group
Go through challenges on Phet (and introduce site)
This is mostly to introduce the Phet site that we’ll use a couple of times during the term as well
Day 5 (Friday, August 30st)
Class meeting
5
Topics
Gauss’s Law
Textbook
Chapter 23
Expected Time
Actual Time
Demos in lecture
Lab
Ponderables
Gauss’s Law Lightening round
20 minutes
Quiz 1
20 minutes
Gauss’s Law Tutorial
70 minutes (possibly less!)
Mini-lectures
Quiz
Simulations
Other
●
●
●
●
Warm Up questions review
○ 10C of charge are placed on a
spherical conducting shell. A particle
with a charge of -3C is placed at the
center of the cavity. The net charge
on the inner
surface of the
shell is:
■ -7C
■ -3C
■ 0C
■ 3C
■ 7C
○ The electric charge per unit area is +σ
for plate 1 and –σ for plate 2. The
magnitude of the electric field
■
associated with plate 1 is σ/εo, and
the electric field lines for this plate are
as shown. When the two are placed
parallel to one another, the magnitude
of the electric field is
■ 2 σ/εo between, 0
outside.
■ 2 σ/εo between, ±
σ/εo outside.
■ zero both between and
outside.
■ ± σ/εo both between and
outside.
none of the above.
Gauss’s Law tutorial (work completed in groups - one worksheet per group) (Jen)
○ Motivate students that first questions are more straightforward than they would expect and not to
spend too much time at beginning
○ Materials - Print out of worksheet
Gauss’s Law Lightning round –
○ Similar to the previous lightning round – just focus on charge distributions with symmetry to show how
quickly the problems can be set up
Quiz 1 – end class with it – make sure that there are at least 20 minutes for the quiz – students can leave when
they are done.
Day 6 (Wednesday, Sept 4th)
Class meeting
6
Expected Time
Topics
Electric Potential
Textbook sections
Ch 23
Demos in lecture
Smoke Stack Problem and Electrostatic
Precipitator
15 minute
30 minutes
Ponderables
Gauss’s Law Ponderables
40 minutes
Mini-lectures
Introduce Electric Potential
15 minutes
Return quizzes
10 minutes
Lab
Quiz
Simulations
Other
●
●
●
●
Return Quizzes
Warm up review
Gauss’s Law Ponderables – Concentric Spheres, E-field vs gravity, inkjet problem
Class Demo - electrostatic Precipitator
○ Materials Needed:
■Van de Graaff
■Smokestack
■Matches
■Incense (paper to burn?
■Holder
■Water source
●
●
More smoke…)
Ponderable - entire class works on this one after the demo
○ Electrostatic Precipitator – do the numbers work out?
Actual Time
Day 7 (Friday, Sept 6th)
Class meeting
7
Topics
Electric Potential
Textbook sections
Chapter 24
Expected Time
Actual Time
Demos in lecture
Lab
E-Field and Potential Lab
40 minutes
Ponderables
Tritium (combining Gauss’s Law and Potential)
30 minutes
Mini-lectures
Pre-Lab discussion on E-fields/measurements
Post-Lab discussion (lab requirements and
wrapup)
10 minutes
10 minutes
Quiz
Simulations
Other
●
Warm-Up questions
○
●
●
Consider two isolated spherical
conductors each having net charge Q.
The spheres have radii a and b,
where b>a. Which sphere has the
higher potential?
■ the sphere of radius a
■ the sphere of radius b
■ They have the same
potential.
○
In a certain region of space the electric potential
increases uniformly from east to west and does not
vary in any other direction. The electric field:
■ points east and varies with position
■ points east and does not vary with
position
■ points west and varies with position
■ points west and does not vary with position
■ points north and does not vary with position
Pre-lab discussion/mini-lecture on lab techniques
E-field potentials introduction and pre-lab discussion (really should take less than 60 minutes)
○ Don’t poke holes through the conductive paper with the probes
○
○
●
This is a qualitative exercise – make sure that you don’t lose the forest for the trees when taking data points
We will share data!
■ A groups- dipoles, B groups-parallel plate configurations and C groups- triangle/line configurations
E-Fields Lab and Potentials (posted on Sakai and in project space)
○
○
○
○
To save time, each group will just do one charge configuration
Scan data sheets to share by end of class – but everything online for students to pick one complete set for the
write up
Shared gdoc for parallel line and concentric circles (students enter during class)
Materials needed:
■
■
●
3 multi-meters, configurations and power supplies per table
Printouts of charge configurations
Post lab wrap up (comparison between groups – short discussion of plots) – what do you expect for the graphs, why?
Day 8 (Monday, Sept 9th)
Class meeting
8
Expected Time
Topics
Capacitors
Textbook sections
Chapter 25
Demos in lecture
Teaser demo – discharge capacitor, hand cranks
20 minutes
Mini-lectures
Capacitors
15 minutes
Quiz
Quiz 2
20 minutes
Electric Potential worksheet
40 minutes
Actual Time
Lab
Ponderables
Simulations
Other
●
Warm-Up review
○
diagram shows four pairs of large parallel
conducting plates. The value of the electric
potential is given for each plate. Rank the
pairs according to the magnitude of the
electric field between the plates, least to
greatest.
○
●
●
●
●
■
■
■
T
h
e
■
■
○
■
■
■
■
■
2, 3, 1, 4
2, 4, 1, 3
3, 2, 4, 1
Choose the correct statement:
A proton tends to go from a region of low potential
to a region of high potential
The potential of a negatively charged conductor
must be negative
If E = 0 at a point P then V must be zero at P
If V = 0 at a point P then E must be zero at P
None of the above are correct
1, 2, 3, 4
4, 3, 2, 1
Start with the Electric Potential Worksheet – group problems solving – one sheet per group
Teaser Demo – large cap discharge with screwdriver
○ Materials needed
■ Large Capacitor
■ Power Supply
■ Big Screwdriver
Mini-lecture on capacitance and break up with demos
○ Hand out hand cranks and 1F Caps to discuss/feel capacitors
■ Make sure there are enough large caps so you can really feel something
○ Mechanical energy -> electrical energy storage
Quiz 2 – make sure to leave 20 minutes
Day 9 (Wednesday, Sept 11th)
Class meeting
9
Topics
Capacitance
Textbook sections
Chapter 25
Expected Time
Actual Time
Demos in lecture
Lab
Capacitor Lab
80 minutes
Energy storage in capacitors,
dielectrics
20 minutes
Quiz review/announcements
10 minutes
Ponderables
Mini-lectures
Quiz
Simulations
Other
●
●
Warm Up and quiz review
○ The plates of an isolated parallel plate
capacitor with a capacitance C carry a
charge Q. The plate separation is d.
Initially, the space between the plates
contains only air. Then, a Teflon
(kappa=2.1) sheet of thickness 0.5d is
inserted between, but not touching, the
plates. How does the electric field and the
stored energy of the capacitor change as a
result of inserting the Teflon sheet?
■ The electric field will decrease
and the energy stored will
increase
■ The electric field will increase
and the energy stored will also
increase.
■ The electric field will decrease and the
energy stored will decrease.
■ The electric field will increase and the
energy stored will decrease.
■ The electric field will not change and the
energy stored will increase.
○
The plates of a parallel plate capacitor with
capacitance C carry a charge Q. What is the
capacitance of the capacitor if the charge is
increased to 4Q?
■ C/2
■ C/4
■ 4C
■ 2C
■ C
Capacitor Lab (all instructors circulate)
○ Start out part 1a as interactive - everyone find XX cap, make measurement, and discuss what is
known, what is unknown, how do we make measurements, etc.
■ Otherwise this particular part of the lab takes them too long – encourage them to get to
part 1b
○ In initial discussion, make sure to have them think about stray capacitance
■ Materials Needed:
● Tupperware containers with misc capacitors
● Capacitance meter per group
● Parallel plate setup per group
● Ruler
● Dielectric sheets
■ Mounted pairs (or 3 if possible) of capacitors (values not important – but mounted helpful
for comparing series to parallel arrangements)
Day 10 (Friday, Sept 13th)
Class meeting
10
Topics
Capacitance
Textbook sections
Chapter 25
Expected Time
Demos in lecture
Actual Time
5-10 minutes
Lab
Ponderables
Capacitor Ponderables
45 minutes
Group Worksheet on Caps in circuits
45 minutes
Mini-lectures
Quiz
Simulations
Other

Warm Up review
o Capacitor B has one-half the
capacitance of capacitor A. How
does the charge on capacitor A
compare to that on B when the
two are connected in parallel
with a battery for a long time?
 The charge on cap A is onefourth the charge on cap B.
 The charge on cap A is onehalf the charge on cap B.
 The charge on cap A is the
same as the charge on cap B.
 The charge on cap A is twice
the charge on cap B.
 The charge on cap A is four
times the charge on cap B.



o Capacitor B has one-half the
capacitance of capacitor A.
How does the charge on
capacitor A compare to that on
B when the two are connected
in series to a battery for a long
time?
 The charge on cap A is onefourth the charge on cap B.
 The charge on cap A is onehalf the charge on cap B
 The charge on cap A is the
same as the charge on cap B
 The charge on cap A is twice
the charge on cap B.
 The charge on cap A is four
times the charge on cap B.
Hand out worksheets for students to work through some short problems on capacitors in
circuits
o Watch on the first question that they consider all different configurations and that
you check for charges on the circuit question
Capacitor ponderables – nerve cell, weather balloon, capacitors vs gravity and arranging
dielectrics (last two are shorter and can be given to the same groups)
End class with resistance, resisitivity, etc. if there is time or continue the next day
o Use Plinko board ?? to demonstrate the random walk/concept of resistance…
Day 11 (Monday, Sept 16th)
Class meeting
11
Expected Time
Topics
Resistance
Textbook sections
Chapter 26
Demos in lecture
Bulb board, Plinko Demo
Lab
Batteries and Bulbs
30 minutes
Bulbs wrap up (with demo board?)
Resistance Mini-Lecture
10 minutes
20 minutes
Warm up Review
5 minutes
Actual Time
20 minutes total
Ponderables
Mini-lectures
Quiz
Simulations
Other





Warm Up review
o A wire of resistance R is stretched uniformly
(keeping its volume constant) until it is twice
its original length. What happens to the
resistance?

It decreases by a factor of 4

It decreases by a factor of 2

It stays the same

It increases by a factor of 2

It increases by a factor of 4
Resistance = Resistivity *
Length/Cross sectional area. After being
stretched, the length doubles and the
cross sectional area is halved.
% Correct: 70
o
Conduction electrons move to the right in
a certain wire. This indicates that

the current density and the electric field
both point right

the current density and the electric
field both point left

the current density points right and the
electric field points left

the current density points left and the
electric field points right

the current density points left but the
direction of the electric field is unknown
Current is direction of positive
charge carriers. Electrons move in the
opposite direction of an electric field.
Start off with Plinko board and a general discussion of resistance and resistivity (focus on material property
vs R for a specific hunk of material)
Batteries and Bulbs short experiment
o Materials needed

Bulbs (CHECK that they are the right number and won’t burn out with 1.5 V batteries)

LED strands

Batteries and battery holders (2-3 per group)
o Emphasize that this is another qualitative lab for the students - they should think through what they
think will happen before making connections/circuits and see if their predictions are correct. It’s ok
to experiment with other combinations as well!!
At the END of the activity, bring out the board with bulbs in parallel and series to help summarize the
findings - interactive demo style (instructors lead together)
Day 12 (Wednesday, Sept 18th)
Class meeting
12
Topics
Finishing Resistance, introducing circuits
Textbook sections
Chapter 26, starting 27
Expected Time
Actual Time
Demos in lecture
Lab
Internal Resistance of Batteries
30 minutes
Ponderables
Resistance Ponderables
45 minutes
Mini-lectures
Kirchoff Laws – clicker questions
15 minutes
Quiz
Quiz 3
20 minutes
Warm up Review
5 minutes
Simulations
Other

Warm Up review
o
It is better to send 10,000 kW of
electric power long distances at
10kV rather than 220 V because





there is less heating in the
transmission wires
the resistance of the wires is less at
high voltages
more current is transmitted at high
voltages
the insulation is more effective at high
voltages
the iR drop along the wires is greater
at high voltages
P=VI=I^2 R To send the power at a lower
voltage, there must be greater current. The
power lost in the lines (as heat) is





proportional to V or I^2 so increasing current
will result in more loss than increasing V.
% Correct: 80
o
As more resistors are added in
series to a constant voltage
source, the power supplied by
the source




increases
decreases
does not change
increases for a time and then
starts to decrease
P=V^2/R Increasing
resistance without changing voltage
decreases the power.
% Correct: 90
Spend some time with the bulb board and wrapping up the lab from the day before to make sure everyone
understands how brightness is related to effective resistance and what is going on (especially after they’ve
had time to think about the ponderables at the end of the lab
Start with the Ponderables for the day (Crushed telephone line, electromagnet, 2 way switch, real circuits)
These aren’t super long
Internal resistance of a battery – this is a combo group demo/hands-on activity rather than the lab from
previous semesters. Students spent too much time trying to make measurements with the shunt resistors,
batteries were being drained and we didn’t end up with that good data in the end. Show them how to make
a single, quick measurement, then let each group collect a bit more data that can be combined into one set
for the class. Analyze as a class or leave as an individual/group activity based on time for the day.
Kirchoff’s Laws introduction – lots of great clicker type questions here to start thinking about circuits
o Students have a big conceptual block with the idea of not knowing ahead of time which direction
the current should be flowing and how to jump in and solve a question
End with Quiz three on capacitors
Day 13, (Friday, Sept 20th)
Class meeting
13
Expected Time
Topics
Finishing Resistance, introducing circuits
Textbook sections
Chapter 27
Actual Time
Demos in lecture
Lab
Resistor Challenge
30 minutes
Ponderables
Resistance Group Worksheet
Resistor cube discussion
40 minutes
35 minutes
Warm up Review
Review quiz
5 minutes
15 minutes
Mini-lectures
Quiz
Simulations
Other

Warm Up review
o
As more resistors are added in series to a constant voltage
source, the power supplied by the source

increases.

decreases.

does not change.

increases for a time and then starts to decrease.
As resistors are added in series the current drawn from the source
decreases. The power supplied is the product of source voltage and
current supplied to the circuit.



o
As more resistors are added in parallel to a constant voltage
source, the power supplied by the source

increases.

decreases.

does not change.

increases for a time and then starts to decrease.
As resistors are added in parallel the current drawn from the source
increases. The power supplied is the product of source voltage and
current supplied to the circuit.
Start the class with the resistor challenge – no prompting, just let them loose. The idea of this activity is can
they translate the sketches of circuits and their mathematical equations into circuits they actually build.
When measuring the built circuits, be careful – things are held together somewhat tenuously by the alligator
clips.
End with the resistor cube as a single ponderable (put the cube under the doc cam so everyone can see it)
o display to students and ask them to consider how to determine the equivalent resistance. Then let
them work in groups for 10-15 minutes before bringing out the voltmeter to show them. You can
take the measurement (and a series of measurements over different combinations of resistors)
under the doc cam so that everyone in the class can see the results
o Important points to note - carbon composite resistors of the large barrel type degrade over time and
can be as much as 30% off from the nominal values implied by the color bands.
o You cannot measure a single resistor within the cube to find the individual resistance since it is part
of the network - have some extra, unsoldered resistors available to show the initial value (and don’t
rely on the color code)
Hand out the resistor group worksheet next – this is applying the same ideas to a slightly more complicated
set of circuits – using Kirchoff’s laws and working with group members to get equations that make sense.
Students have a conceptual block with not knowing ahead of time which direction a current will flow,
especially if there are multiple voltage sources – the idea that the math may, in the end, just give them a
negative value for I is troublesome for many.
Day 14, (Monday, Sept 23th)
Class meeting
14
Topics
Finishing circuits
Textbook sections
Chapter 27
Expected Time
Actual Time
Demos in lecture
Ohm’s Law Lab
60 minutes
Mini-lectures
Lab introduction and wrap up
10 minutes each
Quiz
Quiz 4
20 minutes
Warm up Review
5 minutes
Lab
Ponderables
Simulations
Other

Warm Up review
o



What is the
approximate
equivalent
resistance of the
five resistors
shown in the
circuit?

21 Ohms

7 Ohms

11 Ohms

14 Ohms

19 Ohms
o
Consider the circuit
shown. If the ideal
emf in the circuit is
24 V and the three
resistances are R1
= 2.5 ohms, R2 =
4.0 ohms, and R3 = 6.0 ohms, determine the current
in the 4.0 ohm resistor

1.2A

1.9A



4.0A
6.0A
6.5A
o
What is the current through the 1 Ohm Resistor
below?
 2.8A
 3.0A
 3.4A
 4.3A
 4.8A
Ohm’s Law lab
o
Individual reports/worksheet with directed questions (so no paragraph style discussion section). The same graphs and analysis can be
used from the traditional lab writeup though.
o
Remind the students to check with an experienced person in the room before hooking up an ammeter incorrectly.
o
In the pre-lab discussion, give them an explicit heads up about wiring circuits and how to add in instruments in parallel or series
Time permitting (before the quiz though) – show the decay of a capacitor through a lightbulb and introduce/teaser intro about RC circuits
End with quiz 4 – fill time before we need to start quiz with any remaining questions on Kirchoff’s laws – these warm-up questions might be good
examples to go over during that time (or other similar problems)
Day 15, (Wednesday, Sept 25th)
Class meeting
15
Expected Time
Topics
Finishing circuits/RC time constants
Textbook sections
Chapter 27
Demos in lecture
Decay curve through a light bulb
10 minutes ?
Lab
RC Circuit Lab
40 minutes
Ponderables
RC Circuits worksheet
30 minutes
Mini-lectures
Introduction to RC circuits and time constants
20 minutes
Warm up Review
Review quiz
5 minutes
15 minutes
Actual Time
Quiz
Simulations
Other

Warm Up review
o
In physics lab, Jennifer measured the voltage across an unknown capacitor in an RC circuit,
every ten seconds after a switch in the circuit that allows the capacitor to discharge is
closed. The capacitor was initially fully charged. Using the graph, estimate the time
constant.

7.5 s




o

15 s
30 s
45 s
60 s
What effect, if any, does increasing the battery emf in an RC circuit have on the time to charge the capacitor?

The charging time will decrease because the rate of charge flowing to the plates will increase.

The charging time will decrease because the rate of charge flowing to the plates will decrease.

The charging time will not change because the charging time does not depend on the battery emf.

The charging time will increase because the emf is increased

The charging time will decrease because potential difference across the plates will be larger.
RC Circuits lab
o
Introduce the idea of time constants by showing the bulb brightness as a C discharges through them. Hopefully students will have read,
o
o
o
but I think they are reaching saturation issues before the exam…
If there are no switches set out with the setups, just let students know that they aren’t necessary – you can just close a circuit at the start
of the time keeping.
The oscilloscope station is replaced by a single class demo with the lab pro voltage probe – spend some time describing how
oscilloscopes work – show a few curves and make sure to discuss how to read the screen (mentioning specifically how the trace works at
high speed).
Deliverable here is an individual “short” lab report – one that just answers the specific questions listed out on the single page worksheet.
Day 16, (Friday, Sept 27th)
Class meeting
16
Expected Time
Topics
Finishing all leftover Circuits, starting Magnetism
Textbook sections
Chapter 27 and Chapter 28
Demos in lecture
Lorentz force demos
10 minutes
Lab
Magnetic field investigation
45 minutes
Ponderables
Circuits ponderables (possibly)
30 minutes
Mini-lectures
Introduce Lorentz Force
10 minutes
Actual Time
Quiz
Simulations
Other



No Warm Up quiz for today
Start class with the final ponderables about circuits (if not done earlier!)
o
Real power requirements, wiring a two-way switch
Switch gears and let them investigate (with the guided worksheet) about magnetic fields
o
Groups should have

Magnets (box of bar magnets plus some stronger Neodymium magnets)

Magnaprobes

Magnetic film

One broken cow magnet to share

Compasses
o
Goal is for each group to finish the investigation during class and turn in the worksheet immediately
Introduce the Lorentz force (just in broad terms – demos showing force?)
Day 17, (Monday, Sept 30th)
Class meeting
17
Topics
Exam Review
Textbook sections
Demos in lecture
Lab
Ponderables
Mini-lectures
Quiz
Simulations
Other

No Warm Up quiz for today
No planned activities – student discussions based on questions
Expected Time
Actual Time
Day 18, (Wednesday, Oct 2nd)
Class meeting
18
Expected Time
Topics
Lorentz Force
Textbook sections
Chapter 29
Demos in lecture
Lorentz Forces
Within lecture
Lab
DC Motors and You tube videos
45 minutes
Lorentz Force
20 minutes
Warm Up review
New groups
Exam Return/review
5 minutes
15 minutes
30 minutes
Actual Time
Ponderables
Mini-lectures
Quiz
Simulations
Other





Warm up review
o
In the formula F=qv xB
o
Assume that a uniform magnetic field is

F must be perpendicular to v
directed into this page. If an electron is
but not necessarily to B
released with an initial velocity directed

F must be perpendicular to B
from the bottom edge of to the top edge
but not necessarily to v
of the page, which of the following

V must be perpendicular to B
describes the direction of the resultant
but not necessarily to F
force acting on the electron?

All three vectors must be

Out of the page

To the right
mutually perpendicular

F must be perpendicular to

To the left
v and B

Into the page
Have new student groups up on the projector when students enter the room – give them just a minute to exchange new
contact information with the new group
Return/review midterm exam (releasing solutions? )
Incorporate demos and introduction to Lorentz force into a 10-15 minute introduction
DC Motors activity
o
Examples of a few motors from the department - how do these things work?
o
You Tube video montage of other cool DC motors

made a playlist after a quick search - left the playlist to just play cotinuously during class...
o
Groups then get to make their own

If possible, precut lengths of wire because that took extra time last semester

Find paperclips that are not pre-crimped or just use thicker wire because we had lots of paperclips
break

Pliers were requested by a few groups last time - have one at each table in case??

One group worksheet turned in at the end of the class

bare wire available for groups who want to attempt a homopolar motor design
Day 19, (Friday, Oct 4th)
Class meeting
19
Topics
Lorentz Forces
Expected Time
Actual Time
Textbook sections
Demos in lecture
Lab
Ponderables
Lorentz Force Ponderables – CRTs, mass spec
45 minutes
Mini-lectures
Biot-Savart
20 minutes
Warm Up review
5 minutes
Quiz
Simulations
Other

Warm Up Review
o The path of a charged particle
o
moving parallel to a uniform
magnetic field will be which of the
following:
 Straight line
 Circle
 Parabola
 Elipse
 When v and B are parallel,
there is no magnetic force
A square loop of wire lies in the
plane of the page and carries a
current I as shown. There is a
uniform magnetic field B parallel to
the side MK as indicated. The loop
will tend to rotate:
 About PQ with KL
coming out of the page
 About PQ with KL going
into the page
 About RS with MK coming
out of the page
 About RS with MK going
into the page
 About an axis
perpendicular to the page

Start with the three ponderables (one per group – Airplane flying and generating a voltage, Mass spectrometer and CRTs)
to wrap up the Lorentz Force discussions

Applied problems/setups with Biot-Savart law – lightning round again after initial presentation

If there’s enough time, have the students work on the B fields from currents worksheet (probably save for next day)
Day 20, (Monday, Oct 7th)
Class meeting
20
Expected Time
Topics
Magnetic fields from Currents
Textbook sections
Chapter 30
Actual Time
Demos in lecture
Lab
75 plus minutes
Ponderables
B-fields from Currents worksheet
40 minutes
Mini-lectures
Ampere’s Law
15 minutes
Warm Up review
Lightening Round pt 2
5 minutes
30 minutes
Quiz
Simulations
Other

Warm Up Review
o A hollow cylindrical conductor (inner
radius =a, outer radius = b) carries
a current i uniformly spread over its
cross section. Which graph below
correctly gives B as a function of the
distance r from the center of the
cylinder?




o
A, B, C, D, E
Using Ampere’s law the B field is 0 at r <
than a since no I is enclosed by a loop of
radius a. Between a and b the B field
increases as more current is included.
o
Outside the wire (r>b) the B field falls off as
1/r.
Consider two, long, straight, parallel wires, each carrying a
current I. If the currents are flowing in opposite directions

the two wires will attract each other

the two wires will repel each other

the two wires will exert a torque on each other

neither wire will exert a force on the other

Consider the wires in the plane of this page and
parallel to the top of the page. If the wire closer to the
top carries a current to the R, the magnetic field due
to that current will be into the page at the location of
the second wire whose current flows to the L. The
direction of the force on the second wire will be down
and away from the other wire.
Students have already read the chapter, so we should be able to jump into setting up integrals and go through a
couple of scenarios using both Biot-Savart and Ampere’s Law
After general discussion, start with the worksheet so that students can apply the ideas to fairly short problems
Day 21, (Wednesday, Oct 9th)
Class meeting
20
Topics
Magnetic fields from Currents
Textbook sections
Chapter 30
Expected Time
Actual Time
Demos in lecture
Lab
Magnetic fields from Currents Lab
75 minutes plus
Mini-lectures
Hall probes
15 minutes
Quiz
Quiz 5
20 minutes
Warm Up review
5 minutes
Ponderables
Simulations
Other

Warm Up Review
o
A rectangular loop is placed in a
uniform magnetic field with the
plane of the loop perpendicular to
the direction of the field. If a current
is made
to flow
through
the loop
in the
sense shown by the arrows, the
field exerts on the loop:

A net force

A net torque

A net force and a net
torque

Neither a net force nor a
net torque
o





Two long parallel straight wires
carry equal currents in
opposite directions. At a point
midway between the wires, the
magnetic field they produce is:
zero
non-zero and along a line
connecting the wires
non-zero and parallel to
the wires
non-zero and perpendicular to
the plane of the two wires
none of the above
 Ans: D
 Comment: At the midpoint
between the two wire the
contribution to the magnetic field
from each is equal and in the
same direction.

Introduce the lab by reminding students how Hall Probes work and emphasize the importance of thinking about the
orientation of the measuring device with respect to the equipment as well as the Earth’s magnetic field.
o
Expect some students to forget to zero the equipment and they may need to redo parts of the lab
o
Comparing B vs I isn’t too difficult for the class and the students are able to make accurate predictions on
the whole
o
Understanding the spatial difference between along the axis and radially is challenging for the students –
and predicting what the equations/dependence of the magnetic field will look like is also challenging

Check to see that students do, in fact, find a place that the B field changes sign and that they
understand what this means
o
Measurements with the solenoids are challenging because the students don’t think through the
symmetry/orientation issues and don’t always use the bent tip probes…

If there’s time, continue on to the ponderables

Leave time at end of class for the quiz
Day 22, (Friday, Oct 11th)
Class meeting
22
Topics
Induction
Textbook sections
Chapter 30
Expected Time
Actual Time
Demos in lecture
Lab
Keeping the flux
40 minutes
Ponderables
B fields from currents ponderables
45 minutes
Warm Up review
Quiz review
5 minutes
15 minutes
Mini-lectures
Quiz
Simulations
Other

Warm Up Review
o

A current-carrying loop of wire lies flat on a
o
A circular coil lies flat on a horizontal table.
tabletop. When viewed from above, the
A bar magnet is held above its center with
current travels around the loop in a
the north pole pointing down and released.
counterclockwise direction. What is the
As it approaches the coil, the falling magnet
direction of the magnetic field caused by
induces (when viewed from above)
this current outside the loop? The B field

No current in the coil

Circles the loop in a clockwise

A clockwise current in the coil

A counterclockwise current in the
direction
coil

Circles the loop in a
counterclockwise direction

A current whose direction cannot be

Points straight up
given from the information

Points straight down
Without a lot of intro of new material or prompting, have students move directly to the Keeping the Flux
investigation
o
Materials Needed:

Galvometers

Solenoids

Magnets
o
Students will get caught up in the specific wording of different motions – encourage them to
just investigate all types of motion and not be tied to the ones specifically listed out in the
procedure
o
Students may also get caught up in the fact that many of the meters don’t have numbers –
emphasize the qualitative nature of the investigation
Day 23, (Monday, Oct 14th)
Class meeting
23
Topics
Induction
Textbook sections
Chapter 30
Demos in lecture
Induction demos (magnetic breaks, eddy currents, jumping rings, etc.)
Expected Time
Actual Time
30 minutes
Lab
Ponderables
Induction Ponderables
45 minutes
Mini-lectures
Clicker questions on Lens’ Law
30 minutes
Quiz
Quiz 6
20 minutes
Warm Up review
5 minutes
Simulations
Other

Warm Up Review
As an externally generated B field through
northward. Two coils of wire lie flat on the
a conducting loop increases in mag, the
table, on either side of the wire. When
field produced at points inside the loop by
viewed from above, the induced current
the current induced in the loop must be:
circles

Increasing in magnitude

Clockwise in both coils

Decreasing in magnitude

Counterclockwise in both coils

In the same direction as the applied field

Clockwise in the east coil and

Directed opposite to the applied field
counterclockwise in the west coil

CCW in the E coil and CW in the W

Perpendicular to the applied field
coil
o
A long straight wire lies on a horizontal
table and carries an ever-increasing current

lecture/demo some induction ideas to introduce Lens’ Law – no time at the chalkboard needed – just
go through some cool ideas with the demos

Leads directly into lots and lots of clicker questions/practice with Lenz’s law
o

Then finish with ponderables and the bigger questions
Day 24, (Wednesday, Oct 16th)
Class meeting
24
Topics
AC Circuits
Textbook sections
Chapter 30
Expected Time
Actual Time
Demos in lecture
Lab
Ponderables
LC Circuits worksheet
40 minutes
Mini-lectures
Finish any remaining clicker questions on Lenz’s Law
Inductors as circuit elements plus clicker questions
10 minutes
15 minutes
Warm Up review
Review quiz
5 minutes
15 minutes
Quiz
Simulations
Other

Warm Up Review
o
The diagram shows an inductor that is
part of a circuit. The direction of the emf
induced in the inductor is indicated.
Which of the following is possible?

A battery is used to drive a circuit, but
after a certain amount of time, the
current is zero. When the same circuit is
driven by an ac generator, the current is
non-zero and alternates. Which
combination of elements is most likely to
comprise the circuit?

Resistors only

Inductors only

Capacitors only

A combination of inductors
and resistors
The current is constant and rightward
The current is constant and leftward

The current is increasing and
rightward

The current is increasing and
leftward
Start out with a short introduction to inductors (conceptual – not really getting to circuits or the full
differential equation yet unless we got to introduce a bit more in the previous class) – this gives us the
groundwork for students to start fighting through one of the most difficult concepts in the course


o
Day 25, (Monday, Oct 21st)
Class meeting
25
Expected Time
Topics
AC Circuits
Textbook sections
Chapter 30
Demos in lecture
Transformer demo
With lecture
Lab
RLC Simulation Lab
75 minutes
Phasors – review from lab
10 minutes
Warm Up review
Quiz Review
5 minutes
15 minutes
Actual Time
Ponderables
Mini-lectures
Quiz
Simulations
Other

Warm Up Review

Consider an RLC circuit. The
impedance of the circuit increases if
XL increases.

Always true

True only if XL is less than or equal
to XC
The simulation lab can take up most of the class period if we let it – the students are supposed to
slowly step through an driving frequency for just an R circuit, then a C circuit and finally an L
circuit before attempting the RLC circuit. The simulation itself doesn’t happen until page 7 or so
of the writeup – the simulation itself is an applet from Wolfram and the only issue that students
have is that you can’t change the axis scale directly and the voltage displayed is only the source
(so they can’t directly visualize the phase shift over the L and C), though there is a separate
simulation that displays the rotating phasors.
The transformer section can basically be added in anywhere – it’s a small application that students find
interesting, but if timing makes it more appropriate to put it somewhere else, that’s fine
o
There are ponderables for the transformer concept as well – one is quite short, so we can
have each group do both questions for practice
o



True only if XL is greater than or
equal to XC.

Never true
o
The light bulb has a resistance R,
and the emf drives the circuit with a
frequency w.
The light bulb glows most brightly
at

Very low frequencies

Very high frequencies

the resonant frequency
w=(1/LC)^1/2
RLC Worksheet – work through, in groups, some shorter, more direct questions on RLC series circuits – hopefully
this won’t take a ton of time since they’ve been through the simulation, but it does require them to put everything
together…
Day 26, (Wednesday, Oct 23rd)
Class meeting
26
Expected Time
Topics
AC Circuits
Textbook sections
Chapter 31
Demos in lecture
Oscilloscopes
60 minutes
RLC worksheet
45 minutes
Warm Up review
5 minutes
Actual Time
Lab
Ponderables
Mini-lectures
Quiz
Simulations
Other



Warm Up Review
o
When the switch is closed, the potential
difference across R is

VN2/N1

V N1/N2

V

zero
o
The primary coil of a transformer is
connected to a battery, a resistor, and a
switch. The secondary coil is connected to an ammeter. When the switch is thrown closed, the ammeter
shows

Zero current

A nonzero current for a short instant

Steady current

Since the source of primary voltage
is a battery, the change in flux
through the primary and secondary
is zero except when the switch is thrown. For an instant there is a change in flux
through the primary and secondary inducing a current in the secondary.
Spend some time in class with the LabPro setup as an interactive demo about oscilloscope, what they are used
for, and how we can see, with varying driving frequency, a real change in voltages. We should also spend more
time about reading an oscilloscope screen (thinking ahead to the lab exam).

Also can show this very short video:

circuit-3092/
Another cute and short one: http://www.youtube.com/watch?v=gfUuwnD2-fg (inductor
radio)
http://video.mit.edu/watch/mit-physics-demo-resonant-rlc-
Day 27, (Friday, Oct 25th)
Class meeting
27
Expected Time
Topics
AC Circuits and Maxwell’s equations
Textbook sections
Chapter 31 and 32
Demos in lecture
Transformer
10 minutes
Ponderables
RLC Ponderables – Trap Filter, Transformer, Series Circuit
45 minutes
Mini-lectures
Transformers
20 minutes
Quiz
Quiz 7
20 minutes
Warm Up review
5 minutes
Actual Time
Lab
Simulations
Other




Warm Up Review
o
As the capacitor shown below is charged with a constant current I, at point P there is

a constant electric field.

changing electric field.

constant magnetic field.

changing magnetic field.

changing electric field and a magnetic field.

changing magnetic field and an electric field.

none of the above.
o
Gauss’ law for magnetism tells us:

the net charge in any given volume

that the line integral of a magnetic field around any closed loop must vanish

the magnetic field of a current element

that magnetic monopoles do not exist

charges must be moving to produce magnetic fields
Start out the class with the RLC ponderables (a warmup question with a series circuit and then the trap filter).
o
After students present their answers, spend some time showing them the excel file and how the different
parameters affect the shape of the curve
Maxwell’s equations lecture
You tube videos on levitating frogs, etc – to introduce different magnetism in materials…also superconductivity (for
fun)!
Day 28, (Monday, Oct 28th)
Class meeting
28
Topics
Maxwell’s Equations
Textbook sections
Chapter 31
Expected Time
Actual Time
Demos in lecture
Lab
Ponderables
Power Plant
60 minutes
Mini-lectures
Maxwell’s Equations and Displacement currents
20 minutes, 20 minutes ?
Warm Up review
Review Quiz
5 minutes
15 minutes
Quiz
Simulations
Other

Warm Up Review

Big Power plant ponderable question (everyone in the class works on this one) – it’s a good
summary of all the different ideas that we’ve covered to date but is difficult, even with the
question broken down into parts to discuss.
Day 29, (Wednesday, Oct 30th)
Class meeting
29
Topics
Magnetic Materials
Expected Time
Actual Time
Textbook sections
Demos in lecture
Superconducting demo
20 minutes
Magnetic Materials
20 minutes
Simulations
You tube videos on magnetic levitation and superconductivity
20 minutes
Other
Warm Up Review
Anything we didn’t get to!
5 minutes
Lab
Ponderables
Mini-lectures
Quiz
o
Warm Up Review (no review needed – essay question only)

The diagram shows
two small paramagnetic
spheres, one near
each end of a bar magnet.
Which of the
following statements is true?
 The force on 1 is toward the magnet and the force on 2 is away from the magnet

The force on 1 is away from the magnet and the force on 2 is toward the magnet

The forces on 1 and 2 are both toward the magnet

The forces on 1 and 2 are both away from the magnet

The magnet does not exert a force on either sphere
o
The diagram shows two small diamagnetic spheres, one near each end of a bar magnet. Which
of the following statements is true?

The force on 1 is toward the magnet and the
force on 2 is away from the magnet

The force on 1 is away from the magnet and the
force on 2 is toward the magnet

The forces on 1 and 2 are both toward the magnet

The forces on 1 and 2 are both way from the magnet

The magnet does not exert a force on either sphere

Day 30, (Friday, Nov 1st)
Class meeting
30
Topics
Introduction to Waves
Expected Time
Actual Time
Textbook sections
Demos in lecture
Lab
Polarization Activity
30 minutes
E&M Waves, Polarization
20 minutes
Ponderables
Mini-lectures
Quiz
Simulations
Other

Warm Up Activity
o
How well does your current group work together? Your responses will be kept confidential, so
please answer candidly. We will use this information, along with other factors, to create the final
groups for the semester and we appreciate your honesty.
o
Which gives the largest average energy density at the distance specified and then, at least qualitatively,
the best illumination

A 50W source at distance R

A 100W source at distance 2R

A 200W source at distance 4R
o
Polarization experiments provide evidence that light is

A longitudinal wave

A stream of particles

A transverse wave

Some type of wave

Nearly monochromatic

If there is time, introduce the ideas of radiation and propating E&M Fields plus the polarization
activity (but this can be pushed to Friday if we haven’t finished the transformers or need more
time on some concepts…)
Polarization activity – short investigation where students look at any and all reflections and light
sources in the room with polarizing sheets to try to make some summarizing statements. Looking
at different cell phones and digital watches is also quite interesting here…

Day 31, (Monday, Nov 4th)
Class meeting
31
Topics
Exam Review
Textbook sections
Chapter 28-32
Expected Time
Demos in lecture
Lab
Ponderables
Mini-lectures
Quiz
Simulations
Other

Student Led questions
Full class
No real plan – just follow the students questions in prep for the exam that night
Actual Time
Day 32, (Wednesday, Nov 6th)
Class meeting
32
Expected Time
Topics
E&M waves
Textbook sections
Chapter 33
Demos in lecture
TIR/curved plexiglass?
Lab
Snell’s Law
60 minutes
Snell’s Law
20 minutes
Warm Up review
Exam review
5 minutes
20 minutes
Actual Time
Ponderables
Mini-lectures
Quiz
Simulations
Other

Warm Up Questions
o
The diagram shows total internal reflection. Which one of the following statements is NOT true?





o





Angle AON is the angle of incidence
Angle AON=angle BON
Angle AON must be the critical angle
The speed of light in medium II is greater than that in medium I
If angle AON were increased, there would still be total internal reflection.
When light travels from medium X to medium Y as shown:

Both the speed and the frequency decrease

Both the speed and the frequency increase

Both the speed and the wavelength decrease

Both the speed and the wavelength increase
Review exam
o
Depending on how students did on the test, decide how much time to spend in class on the exam
Start off by introducing radiation, Poynting vectors, etc that wasn’t covered before.
Introduce Snell’s law briefly (the lab will go into more depth!)
Short overview of laser safety and a quick review of the main pitfall of the experiment – setting the acrylic
disc correctly on the rotating plate so that the optic is perpendicular.
The lab works best if the room lights are off and the majority of window shades are closed – but this can
make it hard to read the labs – so suggest students use their smartphones (especially with a red flashlight)
to help during data collection.
Day 33, (Friday, Nov 8th)
Class meeting
33
Topics
Ray Tracing, Thin Lenses
Textbook sections
Chapter 33
Expected Time
Actual Time
Demos in lecture
Lab
Thin Lenses part 1
30 minutes
Ponderables
Optics Worksheet
40 minutes
Mini-lectures
Ray Tracing
20 minutes
Warm Up review
5 minutes
Quiz
Simulations
Other

Warm Up review
o
A virtual image is one








toward which light rays converge but
do not pass through
from which light rays diverge but
not pass through
from which light rays diverge as they
pass through
toward which light rays converge and
pass through
with a ray normal to a mirror passing
through it
o
If a man wishes to use a plane mirror on a
wall to view both his head and his feet as
he stands in front of the mirror, the
required length of the mirror is

Equal to the height of the man

Equal to 1/2 the height of the man

Depends on the distance the man
stands in front of the mirror

Depends on both the height of the man
and the distance from the man to the
mirror
While it makes more sense to continue the optics ponderables discussion from the previous day, we don’t
want to run out of time mid-lab, so explain to class that we’re starting with the lab and will go back to worked
problems afterwards
The lab works best if the room lights are off and the majority of window shades are closed – but this can
make it hard to read the labs – so suggest students use their smartphones (especially with a red flashlight)
to help during data collection.
Trying something new – split into two parts so students really focus on the ray tracing aspect of the lab only
Day 34, (Monday, Nov 11th)
Class meeting
34
Topics
Optics
Textbook sections
Chapter 33/34
Expected Time
Actual Time
Demos in lecture
Lab
Thin Lenses part 2
45 minutes
Ponderables
Optics Ponderables
45 minutes
Quiz 8
20 minutes
Warm Up review
5 minutes
Mini-lectures
Quiz
Simulations
Other

Warm Up Questions –
A lens is used to image an object onto a screen.
Water has an index of refraction greater than air but
If the right half of the lens is covered
less than glass. The light passing through the water

The left half of the image disappears
onto the glass will still be focused but not as close to the

The right half of the image disappears
lens as in air since the light refracts less in going from

The entire image disappears
water to glass than from air to glass.

The image becomes blurred
o
A hollow lens is made of thin glass, as shown. It can

The image becomes fainter
be filled with air, water (n = 1.3) or CS2 (n = 1.6).
o
A parallel beam of light is sent through an
The lens will diverge a beam of parallel light if it is
aquarium If a convex glass lens is held in the
filled with:
water, it focuses the beam

Air and immersed in air

Closer to the lens than outside the water

Air and immersed in water

At the same position as outside the water

Water and immersed in CS2

Farther from the lens than outside the

CS2 and immersed in water
water

CS2 and immersed in CS2

While the ponderables are from the previous couple of days, just to make sure there’s enough time to collect data,
start with the lab and then move to the ponderables. The lab itself shouldn’t take as long with only part 2 to go
over.

Thin Lenses lab –
o
This is one of the best, hands-on labs that we have – the students really get an understanding of ray
tracing with the light boxes. It is a bit difficult to work in the dark and so we have to watch to make sure
that no one gets caught up being overly detailed and loses the big picture
o
There is a premade worksheet for students to record their data and answer short questions – the write up
shouldn’t be long for this lab…
o

Start the faster groups off with the ponderables if necessary – they can always do more than one
– the swimming pool will take them more time to set up a diagram and then think about the
algebra
Day 35, (Wednesday, Nov 13th)
Class meeting
35
Topics
Images – Prisms and Magnifying glasses
Textbook sections
Chapter 34
Expected Time
Actual Time
Demos in lecture
Lab
Prism Investigation
Magnifying glass investigtion
30 -40 minutes
30 -40 minutes
Lab Exam review
30-50 minutes
Warm Up review
Quiz Review
5 minutes
15 minutes
Ponderables
Mini-lectures
Quiz
Simulations
Other




Warm Up Questions
o
A girl is standing in front of a concave mirror. Consider two rays of light, one from her nose and one from
her mouth, that are parallel as they are traveling toward the mirror. These rays will come together

at the focal point

at the center of curvature

at the image point

behind the mirror if she is too close to the mirror
o
A fish swims beneath the surface of the water at P. An observer at O sees the fish at

A greater depth than it actually is

The correct depth

A smaller depth than it actually is
Magnifying glass investigation – the students are asked to, in each group, determine the magnification of some
lenses and think through their own procedures
o
The write up for this is a worksheet style – one per group is plenty. They should be able to finish this in
class and hand it in immediately, no extra homework or analysis
o
The big stumbling block for most students on this investigation is trying to determine the maximum
magnification achieved – what can your eye see clearly and how do we measure it? By looking at a
ruler, you can get a sense of scale (if students get stuck)
The next activity is also hands on – working with prisms. Depending on the flow of the class it might make sense
to come together as a class and cover the lab exam between the two experiments (so they don’t blend together) or
just to let groups work from one to the next, depending on different working speeds.
o
The prism investigation is also a worksheet based investigation – with questions for the group. This has,
in addition, some ponderables at the end. Groups who work quickly can start on those ponderables, the
rest will just have them as homework – you don’t have to give enough time for everyone to complete the
questions in class.
Lab exam review –
o
Stress the importance of labeling and always including uncertainties. Explain that this practicum will be
graded on their ability to make measurements accurately, not just use the equipment but that partial
credit is available on each and every question.
o
Have some example pieces of equipment out for students to work with/ask questions about?
Day 36, (Friday, Nov 15th)
Class meeting
36
Expected Time
Actual Time
Topics
Textbook sections
Demos in lecture
Lab
Ponderables
Mini-lectures
Quiz
Simulations
Other


LAB EXAM
Warm Up Questions
o
No warm-ups for today
Lab exam
o
Open books, open internet, open anything except for classmates
o
Only issue for proctoring is to make sure there is equal access to the equipment for all students
Day 37, (Monday, Nov 18th)
Class meeting
37
Expected Time
Topics
Interference
Textbook sections
Chapter 35
Demos in lecture
Thin films with clear nailpolish or soap or something?
15 minutes
Ponderables
Thin Films group worksheet
40 minutes
Mini-lectures
Introduce interference
20 minutes
Warm Up review
Review Lab exam
5 minutes
30 minutes
Actual Time
Lab
Quiz
Simulations
Other
o
o
In order to produce a sustained interference pattern by light waves from multiple sources, which of the
following criteria must be met?

Sources are coherent

Sources are monochromatic

Both choices are valid

None of the choices above are valid
Consider two identical microscope slides in air illuminated with monochromatic light. The bottom slide is
rotated (counterclockwise about the point of contact in the side view) so that the wedge angle gets a bit
smaller.






What happens to the fringes?
They are spaced farther apart
They are spaced closer together
There is no change

Total constructive interference occurs at points where the separation between the
slides is equal to the odd half-integer multiple of the wavelength. As the angle
becomes smaller, these points move further apart.
Start out class with an introduction to interference and how to think about path length differences
Let groups work through the group worksheet together to apply the concepts on fairly straightforward questions
Move to the Blue Morpho butterfly ponderable that requires looking at multiple possible layers and interferences
Day 38, (Wednesday, Nov 20th)
Class meeting
38
Expected Time
Topics
Interference Cont/Diffraction
Textbook sections
Chapter 36
Demos in lecture
Fun with laser pointers (and photoluminescent posterboard)
Possible butterfly or peacock feather?
10 minutes
10 minutes
Ponderables
Optics Ponderables – blue morpho and reflections
45 minutes
Mini-lectures
Introduce Diffraction
20 minutes
Warm Up review
5 minutes
Actual Time
Lab
Quiz
Simulations
Other

Warm Up Questions
o
A diffraction grating is illuminated with yellow
light at normal incidence. The pattern seen
consists of three yellow spots, one at 0 degrees
(straight through) and one each at ±45°. You
now add red light of equal intensity, coming in
the same direction as the yellow light. The new
pattern consists of

red spots at 0° and ±45°
yellow spots at 0° and ±45°
orange spots at 0° and ±45°
an orange spot at 0°, yellow spots
at ±45°, and red spots slightly
farther out
an orange spot at 0°, yellow spots at
±45°, and red spots slightly closer in






Blue light of wavelength λ passes through a single
slit of width a and forms a diffraction pattern on a
screen. If the blue light is replaced by red light of
wavelength 2λ , the original diffraction pattern is
reproduced if the slit width is changed to

a/4

a/2

no change is necessary

2a

4a

There is no width that can be used to
reproduce the original pattern

The angles where dark fringes appear vary
as λ/a
Start the class finishing up interference with the ponderables
Spend some time lecturing/explaining about diffraction (possibly group interactive demo with
different slits projected onto the wall and class makes a prediction each time
o

o
Day 39, (Friday, Nov 22th)
Class meeting
39
Topics
Diffraction
Textbook sections
Chapter 36
Expected Time
Demos in lecture
Lab
Diffraction Lab
60 minutes
Ponderables
Mini-lectures
Leftovers?
Quiz
Simulations
Other



Warm Up review
5 minutes
Warm Up Questions
Segue into lab – have students move to hallway to do analysis (room is too dark)
o
Use the whiteboards as targets with the worksheets taped onto them
o
Order that they go through slits doesn’t matter
Lab should only take about 20 minutes to collect data but always takes longer!
Actual Time
Day 40, (Monday, Nov 25th)
Class meeting
40
Topics
Diffraction
Textbook sections
Chapter 36
Expected Time
Demos in lecture
Lab
Ponderables
Diffraction ID Challenge
30 minutes
Quiz 9
20 minutes
CSEM/reviews
45 minutes
Mini-lectures
Quiz
Simulations
Other
Actual Time
Day 41, (Monday, Dec 2nd)
Class meeting
41
Expected Time
Actual Time
Topics
Textbook sections
Demos in lecture
Lab
Ponderables
Mini-lectures
Quiz
Simulations
Other

Lab Tours
Field Trip day
Day 42, (Wednesday, Dec 4th)
Class meeting
42
Expected Time
Actual Time
Topics
Textbook sections
Demos in lecture
Lab
Ponderables
Mini-lectures
Quiz
Simulations
Other

Final Exam Review
No warm ups today – student led questions/discussions (can post a question or two on
Sakai about success of lab tour)