## Thursday, June 27, 2019

### AP Physics C new Manual Part 2

This is a continuation of the original post discussing the changes/tweaks to the AP Physics C Mechanics curriculum by the College Board.

The Electricity & Magnetism curriculum is in the same new format as the Mechanics one. There are the same four Big Ideas that are across all the units:

 Unit 1:Electrostatics Unit 2: Conductors, Capacitors, Dielectrics Unit 3: Electric Circuits Unit 4: Magnetic Fields Unit 5: Electromagnetism Big Idea 1: Change (CHA) Interactions produce changes in motion. X Big Idea 1: Force Interactions (INT) Forces characterize interactions between objects or systems. X X X Big Idea 3: Fields (FLD) Fields predict and describe interactions. X X X X X Big Idea 4: Conservation (CON) Conservation laws constrain interactions X X X X X

With only five units instead of the seven  in Mechanics each unit contains more Leaving Objectives but I found the Essential Knowledge section a bit more sparse. There seemed to be more times that the equation was thrown down and then "using calculus" was meant to explain more of the content. I mean, it does, but I think the content needed under Essential Knowledge is more apparent in Mechanics than in E&M. Unlike in  Mechanics I don't recall seeing any additional equations not on the supplied equation sheet either.

Unit 1: Electrostatics (pdf or Google Doc)
Unit 2: Conductors, Capacitors, Dielectrics (pdf or Google Doc)
Unit 3: Electric Circuits (pdf or Google Doc)
Unit 4: Magnetic Fields (pdf or Google Doc)
Unit 5: Electromagnetism (pdf or Google Doc)

## Wednesday, June 19, 2019

### The Light Playlist of Phyz

Somewhere in the end-of-the-year rush, I failed to post the ever-important Light Playlist, suitable for background play during light and optics labs. I apologize for my tardiness in this matter.

Previously posted playlists: Waves & Sound, Magnetism, and Electricity. There's a "playlist" topic link below and to the right as well.

## Tuesday, June 18, 2019

### The best laid plans

It's true: I see the world in physics. You might, too. So when I saw a thing at Panera Bread, I spun it into a narrative that's too good to verify. Meaning I could have it a bit wrong, but it feels right. It's 2019, so... good enough.

In any case, here's the observation: an LCD screen in portrait orientation goes dark when viewed through polarized sunglasses. Unless you tilt your head sideways!

My story is that the LCD was manufactured to be used in landscape orientation, as is the case for 99.9% of such displays. In that orientation, the polarization inherent in LCDs was set to be viewable even through polarized sunglasses. But the Panera queue application required portrait mode. Hence the trouble.

And honestly, if you're indoors at Panera, why are you wearing your sunglasses? (Actually, if they're prescription, keeping them on while waiting for your coffee might not be so unreasonable.)

Note that your modern smartphone can be viewed in portrait or landscape through polarized sunglasses. Their displays have been depolarized! Some kind of sorcery is at work here.

## Tuesday, June 11, 2019

### AP Physics C new manual

The College Board has redesigned (or tweaked?) the AP Physics C Mechanics and Electricity & Magnetism exams for the 2019-2020 school year. The instructors have access to the Course and Exam Description which has been expanded greatly. The 2014 version was 69 pages for both Mechanics and Electricity & Magnetism. The new versions are 174 and 170 pages each, respectively. Going through them is part of my summer plans (exciting I know) and I wanted to share my first impressions, resources, etc.

First of all, the organization is way different. The old version had a few pages on lab and course suggestions (you need money for lab supplies, the class takes lots of time, etc.) and gave a breakdown of the percentage of the exam by topic. Then came several pages of an outline of objectives of the "Students show understand/be able to..." variety. I had retyped these for my students and passed them out at the beginning of each unit. I thought it was important for students to see exactly what could be asked of them on the exam and also what was outside the scope.

Here are the old versions if you're interested:
A. Kinematics
B. Newton's laws of motion
C. Work, Energy, Power
D. Momentum
E. Circular Motion and Rotation
F. Oscillations  & Gravitation

The new version has a lot more information about the logistics of teaching the course. There is suggested pacing, although the range for each unit is large because they recognize that AP Physics C can be taught as a one year or two year course. The course is organized into 7 units, essentially the same topic breakdown as above. Within each unit are subtopics listings with learning objectives under each. Each subtopic has a Enduring Understanding statement which is defined as "long-term takeaways related to the big ideas that leave a lasting impression on students." Each Enduring Understanding comes with Learning Objectives and Essential Knowledge statements. The Learning Objectives have the same purpose as the old ones, the Essential Knowledge is more like a summary or clarification statement. These list the equations that represent the relationships described in the Learning Objectives, some of which are on the equation sheet while some are not. Each unit has a different amount of Topics and Learning Objectives. Some concepts seem to have more emphasis than they used to, for example resistive (drag) forces Under Unit 2 Newton's Laws of motion.

The lab related objectives have also been updated to be Science Practices, a list of skills related to both physical lab skills and also critical thinking and problem solving. There is a whole table that outlines the 7 main practices and the skills required for each. I plan to make a copy of it for my students. The old lab objectives were not as detailed, as a comparison:

Old practices:
3. Analyze data - Students should understand how to analyze data, so they can:
a) Display data in graphical or tabular form.
b) Fit lines and curves to data points in graphs.
c) Perform calculations with data.

d) Make extrapolations and interpolations from data.

New practices:
Practice 4: Data Analysis
Analyze quantitative data represented in graphs.
4.A Identify and describe patterns and trends in data or a graph.
4.B Demonstrate consistency between different graphical representations of the same physical situation.
4.C Linearize data and/or determine a best fit line or curve.
4.D Select relevant features of a graph to describe a physical situation or solve problems.

4.E Explain how the data or graph illustrates a physics principle, process, concept or theory.

Across all 7 units are four "Big Ideas" that remind me of the Cross Cutting Concepts of NGSS. The Learning Objectives for each unit's subtopic fit under one of these Big Ideas. A handy table is included:
 Unit 1: Kinematics Unit 2: Newton's Laws of Motion Unit 3: Work, energy, power Unit 4: Systems of particles, linear momentum Unit 5: Circular motion and rotation Unit 6: Oscillations Unit 7: Gravitation Big Idea 1: Change (CHA) Interactions produce changes in motion. X X X Big Idea 1: Force Interactions (INT) Forces characterize interactions between objects or systems. X X X X X Big Idea 3: Fields (FLD) Fields predict and describe interactions. X Big Idea 4: Conservation (CON) Conservation laws constrain interactions X X X X

Overall the unit outlines and supplemental materials looks well designed and flushed out. There are reminders everywhere to view the online materials available for teachers and students. Students will have access to online practice multiple choice and free response questions that are similar in style to the AP exam. It is suggested that you assign these practice problems for homework but specifically states that it should not be graded other than for participation points. There is a page of sample instructional activities, notes space and more. All like the ideal unit outlines we were supposed to learn to make after the credential program.

All in all I like the addition of information. The layout and new terms will take some getting used to and I'm still deciding what to give my students. I typed up each unit's topic, Enduring Understanding, Learning Objectives and Essential Knowledge for Mechanics. That... took awhile. On one hand I like the Essential Knowledge as background information for my students but I also worry it is too much detail for them and they won't look at it. I typed up the Science Practices (lab skills) and also separated the Learning Objectives into a separate document. And since I typed it up, you won't have to! I'll get to E&M later and I'll be sure to post it here as well.

All Learning Objects (pdf or Google doc)
Science Practices (pdf or Google doc)
Unit 1: Kinematics (pdf or Google doc)
Unit 2: Newton's Laws of Motion (pdf or Google doc) and Circular Motion (pdf or Google doc)
Unit 3:Work, Energy and Power (pdf or Google doc)
Unit 4: Systems of Particles [aka Center of Mass] (pdf or Google doc) and Linear Momentum (pdf or Google doc)
Unit 5: Rotation (pdf or Google doc)
Unit 6: Oscillations (pdf or Google doc)
Unit 7: Gravitation (pdf or Google doc)