Tag Archives: physics

AP Physics 2 Reflection

On the eve of the first day of school, I felt that I better capture my thoughts on AP Physics 2 last year. My perspective may be different than other’s (at least different than the vocal minority(?) on the AP Teacher Community).

I started last year eagerly anticipating the new AP Physics 2 course. For the past seven years, I had taught some type of a second-year physics course. For most of that time, I taught what we called Advanced Physics, a one-semester course after which some of my students would take the AP Physics B exam. For a couple of years, I taught an official, year-long, AP Physics B course. I felt that the AP Physics B course had too much content to cover well, even as a second-year course. This was compounded by the mismatch between the groups of student that enrolled in the course. About a third of the students had previously taken our General Physics course, and two-thirds, Honors Physics. The Honors Physics students had studied additional units not part of the General Physics course. As a result, for some “review” units in AP Physics B, the pace was much too fast for those from General Physics and much too slow for those from Honors Physics.

The new AP Physics 2 course contained less content. In addition, the emphasis shifted towards deeper conceptual understanding of physics rather than numeric or algebraic problem solving. As a result of these changes, I felt that I could at last integrate much more of Modeling Instruction into a second-year physics course. I wasn’t too concerned about the shift towards deeper conceptual understanding since I had been moving my course in that direction for the past couple of years based on student performance on the AP Physics B exam. My students had done extremely well on the free response portion of the AP Physics B exam; therefore, I had adjusted class to focus more on conceptual understanding since the greatest area for growth was on the multiple choice portion of the exam. During the summer of 2014, I attended an AP Summer Institute to learn more about the new course. As a result of all of this, I started last year much more excited than anxious.

Reflecting back on AP Physics 2 last year, it was my favorite year teaching a second-year physics course. That said, while many aspects of the course worked well, there are definite areas for me to improve this year.

What Worked

Peer instruction was very effective at developing students’ conceptual understanding. Of all the various types activities done in class, students ranked peer instruction as the most helpful (over 75% of students agreed with the statement “Participating in peer instruction of conceptual questions helped me understand the material.” on the end-of-year survey). The manner by which I conduct peer instruction is strongly influenced by the research of Stephanie Chasteen who writes at sciencegeekgirl. The questions I use are a combination of Paul Hewitt’s Next-Time Questions, the end-of-chapter conceptual questions in Knight’s College Physics text, and those in clicker questions banks from CU Boulder and OSU.

The number and variety of lab activities also worked well. Some labs were informal stations, some typical Modeling Instruction paradigm labs, some lab practicums. With less content, we had time for more, and deeper, labs. Some of the labs and skills involved went beyond that required by the AP Physics 2 curriculum, but some of these were the students favorite. We will continue to explore computational modeling, build more advanced circuits on breadboards, and explore particle physics.

What Didn’t Work

Building my standards, and grading, on the Enduring Understanding defined for each Big Idea did not work well. While my goal was for students to see the connections between the various content areas and appreciate the Big Ideas, students shared that organizing the standards and grades in this manner didn’t help accomplish this. It did result in a lot of extra work for me. After the fall semester, I mostly abandoned this approach. Below, I’ll explain my approach for this year.

Whiteboarding homework problems did not work well. My approach was for six groups of students to prepare and present whiteboards based on assigned homework problems. This didn’t work well because too few students had done the homework problems in advance of whiteboarding. As a result, most of the group would watch those who had done the problems prepare the whiteboards and didn’t really understand the solution. This issue was compounded when whiteboards were presented. Too few students had struggled with the problem in advance to result in a good discussion. This wasn’t the case every time, but much too often.

What I’m Trying This Year

My attempts to prepare students for the free response portion of the AP Physics 2 exam fell somewhere between working and not working. I overestimated students’ ability to write clear, concise, and correct free responses. As a result, I didn’t dedicate sufficient time to practicing this skill. What did work well was using Socrative to share student responses and peer critique these responses. We will do this much more this year.

While my attempts to reinforce the Big Ideas by structuring standards and scores around Enduring Understandings didn’t work, emphasizing the AP Science Practices did work well. Inspired by Chris Ludwig’s work with portfolios and our discussion at NSTA earlier this year, my students will create a lab notebook and portfolio on their own Google Site. The notebook will capture all the labs and the portfolio will be a curated collection of labs that demonstrate their performance of the various AP Science Practices. I hope to share the details of this soon.

To improve the value of whiteboarding, I’m making several changes. Instead of six groups preparing and presenting six problems, groups will prepare and present only two problems. Each problem will be prepared by three groups. The problem won’t be assigned as homework. Rather, we will spend more class time as each group works together to solve the problem. A randomly selected member of each group will be responsible for presenting the whiteboard, and the class will focus on comparing and contrasting solutions between the various groups in addition to the solution itself.


The average AP Physics 2 scores were about a point lower than the previous year’s AP Physics B scores (3.344 vs. 4.484). However, as I considered the standards and expectations for AP Physics 2 compared to AP Physics B and carefully considered each of my students, their scores were what I expected, except for a few.


I’m thrilled with the new AP Physics 2 class and excited about teaching this course for the second time. All that I miss from AP Physics B is a huge collection of exam questions from which I could build my own assessments. My one wish is that the College Board releases additional questions as questions in the style of the new exam are very difficult to create. I hope that the changes that I have planned for this year help students to develop an even stronger and deeper understanding of physics and proficiency in science practices than last year’s. If you are interested in more detail about my approach last year, my 180 blog focused solely on AP Physics 2.

Chromebook Toolchain for AP Physics

This fall, my AP Physics 2 classes will be using Chromebooks as part of my school district’s 1:1 pilot. Chromebooks were new to me; so, it took some time this summer to find the apps to support the workflow I want for this class. While I’m sure the toolchain will change throughout the semester, and there will be surprises (both pleasant and otherwise), here is the starting toolchain:

  • Canvas. Everything starts and ends with this learning-management system.

We will do a lot of lab activities. The workflow depends on the amount of data acquired and the level of graphical analysis required. The start of the workflow is the same:

  • LabQuest 2. Vernier’s LabQuest 2 can create its own ad-hoc network or connect to the school’s wireless network. The LabQuest 2 hosts its own web page as part of their Connected Science System. Students can then access the device, the data, and graphs via Chrome. Data and graphs can be exported to the Chromebook via the web page.

The next tool depends upon the lab. For some labs, the data and graphs produced on the LabQuest 2 are sufficient. Students will import these into their Google Document and create whatever is required for their lab report. If additional analysis is required and the data sets are relatively small:

If data sets are large or more sophisticated analysis is required:

  • Plot.ly. Plot.ly seemed to explode onto the education scene this summer, or maybe I was just paying more attention. Data exported from the LabQuest 2 can easily be imported into Plot.ly. Like Desmos, graphs can be shared via a link and an image can be embedded in the Google document. Plot.ly can also embed its graphs in an iframe, but I couldn’t find a way to embed that in a Google document as opposed to a web page. Fran Poodry from Vernier made a great screencast demonstrating the integration of the LabQuest 2 and Ploy.ly.

Regardless of the analysis performed, in the end, students create their lab report in Google docs and submit it via Canvas.

Another important aspect of class is the exploration and modification of computational models. In the past, we’ve used VPython. I had to find an alternative that would be compatible with Chromebooks:

  • Glowscript. Glowscript is the up-and-coming platform for computational models with the advantage that it runs in a browser that supports WebGL. I’m not a huge fan of JavaScript syntax for novice programmers; so, we will be using CoffeeScript instead. I didn’t write as many starting models over the summer as I had hoped, but I did at least verify that complicated models can be ported.

Peer instruction is one of the most effective and popular classroom activities that we do. In the past, I’ve used handheld clickers. This year, we will use the Chromebooks:

  • InfuseLearning. There are a number of web apps in this space, but I selected InfuseLearing because it allows the creation of spontaneous questions, supports a variety of answer methods including drawing and sort-in-order. Pear Deck looks promising, but I don’t want to be forced to create my set of questions ahead of time.

For notes in class, I’ll leave it up to students to use whatever tool works best for them (including paper and pencil). I’ll suggest they at least take a look at:

  • Evernote. I love Evernote and use it all the time for all sorts of stuff.

I do provide students with PDFs of my slides. I can envision that students may want to annotate these PDFs or other handouts. Surprisingly, this was the hardest tool to find:

  • Crocodoc. The free personal version allows students to upload a PDF, annotate it, and export their annotated version. Other tools I explored are Notable PDF. This requires paid licenses to be useful. We may try this out if we find Crocodoc lacking.

A couple of other tools that looks interesting, but I’m not sure if they fits into the toolchain for my class is:

  • Doctopus. I think Canvas assignments and SpeedGrader cover everything that I personally would do with this app.

  • 81Dash. Private back-channeling app.

I’m sure I will learn of new tools throughout the semester and I’ll make adjustments to the toolchain. If you are using Chromebooks, please share your favorite apps below in the comments!

Standards for AP Physics 2

I floated this idea on Twitter a couple of weeks ago and have decided to give it a try. Historically, I’ve grouped my assessment standards into unit-centric categories. In an attempt to emphasize the big ideas and science practices more strongly, I’m going to group standards by the Big Ideas defined by the College Board for AP Physics 2. My assessment standards are the Enduring Understanding defined for each Big Idea. The Essential Knowledge items and Learning Objectives are too fine grained for my style of standards-based assessment and reporting, especially for an AP class where I want students to focus on the combination of multiple concepts.

There will be multiple assessments (labs and exam questions) for each standard. A given assessment will focus on a subset of learning objectives for that standard. As a result, there will be multiple scores for each standard in the grade book. I hope this will give students more insight into their strengths and areas for improvement as they progress throughout the course. I’ll still have reassessments.

The weights for each Big Idea category will not be the same, but I’m going to do more planning before assigning them. I also need to see how these standards are split between the fall and spring semesters.

If you think I’m courting disaster with this plan, please let me know. If you adopt a similar approach for your AP Physics class, please remember I’ve never tried this before!

  • 1: Objects and systems have properties such as mass and charge. Systems may have internal structure.
    • 1.A: The internal structure of a system determines many properties of the system.
    • 1.B: Electric charge is a property of an object or system that affects its interactions with other objects or systems containing charge.
    • 1.C: Objects and systems have properties of inertial mass and gravitational mass that are experimentally verified to be the same and that satisfy conservation principles.
    • 1.D: Classical mechanics cannot describe all properties of objects.
    • 1.E: Materials have many macroscopic properties that result from the arrangement and interactions of the atoms and molecules that make up the material.
  • 2: Fields existing in space can be used to explain interactions.
    • 2.A: A field associates a value of some physical quantity with every point in space. Field models are useful for describing interactions that occur at a distance (long-range forces) as well as a variety of other physical phenomena.
    • 2.C: An electric field is caused by an object with electric charge.
    • 2.D: A magnetic field is caused by a magnet or a moving electrically charged object. Magnetic fields observed in nature always seem to be produced either by moving charged objects or by magnetic dipoles or combinations of dipoles and never by single poles.
    • 2.E: Physicists often construct a map of isolines connecting points of equal value for some quantity related to a field and use these maps to help visualize the field.
  • 3: The interactions of an object with other objects can be described by forces.
    • 3.A: All forces share certain common characteristics when considered by observers in inertial reference frames.
    • 3.B: Classically, the acceleration of an object interacting with other objects can be predicted by using Newton’s Second Law.
    • 3.C: At the macroscopic level, forces can be categorized as either long-range (action-at-a-distance) forces or contact forces.
    • 3.G: Certain types of forces are considered fundamental.
  • 4: Interactions between systems can result in changes in those systems.
    • 4.C: Interactions with other objects or systems can change the total energy of a system.
    • 4.E: The electric and magnetic properties of a system can change in response to the presence of, or changes in, other objects or systems.
  • 5: Changes that occur as a result of interactions are constrained by conservation laws.
    • 5.B: The energy of a system is conserved.
    • 5.C: The electric charge of a system is conserved.
    • 5.D: The linear momentum of a system is conserved.
    • 5.F: Classically, the mass of a system is conserved.
  • 6: Waves can transfer energy and momentum from one location to another without the permanent transfer of mass and serve as a mathematical model for the description of other phenomena.
    • 6.A: A wave is a traveling disturbance that transfers energy and momentum.
    • 6.B: A periodic wave is one that repeats as a function of both time and position and can be described by its amplitude, frequency, wavelength, speed, and energy.
    • 6.C: Only waves exhibit interference and diffraction.
    • 6.E: The direction of propagation of a wave such as light may be changed when the wave encounters an interface between two media.
    • 6.F: Electromagnetic radiation can be modeled as waves or as fundamental particles.
    • 6.G: All matter can be modeled as waves or as particles.
  • 7: The mathematics of probability can be used to describe the behavior of complex systems and to interpret the behavior of quantum mechanical systems.
    • 7.A: The properties of an ideal gas can be explained in terms of a small number of macroscopic variables including temperature and pressure.
    • 7.B: The tendency of isolated systems to move toward states with higher disorder is described by probability.
    • 7.C: At the quantum scale, matter is described by a wave function, which leads to a probabilistic description of the microscopic world.

AP Physics B End-of-Year Survey Results

Before I start planning for the new AP Physics 2 class in detail, I first reviewed the end-of-year feedback from my AP Physics B students. I made very few changes in this course last year since two years ago went well and this is the last year for the course. In the following charts, a “1” represents strongly agree and a “5” represents strongly disagree.

A majority of the students didn’t read the textbook much. I’m not surprised by this since I don’t push the textbook very much. It is dated and doesn’t align much with my pedagogy. Students rely on other resources from class much more. However, I do think it is important that students learn to read a college-level text. I’m extremely pleased that next year we will have Knight’s College Physics text which I will incorporate much more strongly into the new AP Physics 2 course.

Screen Shot 2014 06 24 at 10 25 05 AM

I assigned conceptual questions from the textbook. Again, most students didn’t answer these. However, those that did, found them valuable. The conceptual questions assigned from the text were different than those I used for peer instruction. I may make use Knight’s conceptual questions as some of the peer instruction questions next year, which I expect will motivate students to answer them.

Screen Shot 2014 06 24 at 10 25 12 AM

Many students did not solve the homework problems. Those that did, found them helpful. Honestly, with few exceptions, I’m fine with this. I don’t grade homework and want students to learn to determine if they need the additional practice or not. Most of my students learn to self assess and make good choices in this area.

Screen Shot 2014 06 24 at 10 25 21 AM

Lab activities and practice quizzes are all about learning and not graded. Students found the quizzes (old AP free response questions) particularly useful. I’m really going to miss having a huge collection of old free response questions next year in AP Physics 2.

Screen Shot 2014 06 24 at 10 25 28 AM

I wanted to highlight peer instruction specifically. I was surprised last year how valuable students found peer instruction focused on conceptual questions. This year’s feedback was just as strong. In the free-form comments in the section “What are some things that I should keep doing next year?” peer instruction was mentioned more than anything else. I think focusing on conceptual questions through peer instruction will be even more important in the new AP Physics 1/2 courses which emphasize a deep, conceptual understanding. Perhaps, since this has been a focus of my class for the past two years, is why I’m freaking out much less than other AP physics teachers after taking the AP practice exams.

Screen Shot 2014 06 25 at 9 44 01 AM

Strong positive feedback on the summative labs for the course. I plan to incorporate those that are relevant into the AP Physics 2 course next year. We’ve already incorporated some of them into the AP Physics 1 course. The choices for the “I found the summative labs:” question ranged from too challenging (1) to too easy (5). In similar fashion to my AP Computer Science students’ feedback, students found the written feedback provided via Canvas helpful in developing their understanding of the material.

Screen Shot 2014 06 25 at 9 44 16 AM

A couple of surprises in terms of which labs students marked as their favorites. The Simple Harmonic Motion lab has students develop a mathematical model by modifying various physical characteristics of a mass on a vertical spring. I was surprised it wasn’t more popular. We also did this lab in Honors Physics (AP Physics 1) this year. I was surprised that the diffraction and interference lab was in the top 5. I don’t feel that it is one of my strongest labs, yet students disagree. No surprise that the capstone project was the run-away favorite. I will keep that in the AP Physics 2 class. I’m planning to continue to do the CMS Masterclass, which focuses on particle physics, in AP Physics 2 as well. Hopefully, we can do this as part of a field trip to Fermilab next year. We didn’t have a field trip to Fermilab this year. The most common suggestion in the section “What are some things that I should try next year?” was to have a field trip to Fermilab. I hate to lose the Projectile Motion lab. The only way it would be part of AP Physics 2 is if I use it as a lab for an introductory unit on computational modeling. It is too advanced for AP Physics 1 in the projectile motion unit.

Screen Shot 2014 06 24 at 10 26 23 AM

Pleased that so many students are considering pursuing STEM-related fields, but not too surprised since this is a second-year physics course.

Screen Shot 2014 06 24 at 10 26 30 AM

Strong positive feedback on standards-based assessment and reporting. Summative labs and exams were scored on a 1-5 scale. Each unit that consisted of one exam and one lab. I’m considering changing this next year and having a standard for each AP Physics 2 Essential Knowledge item grouped into categories based on each AP Physics 2 Big Ideas. I feel this will emphasize science practices and connections between concepts rather than my traditional approach focused on units and content.

Screen Shot 2014 06 24 at 10 26 35 AM

This summer I have a lot of work to do developing the new AP Physics 2 course which includes incorporating a new textbook and much more Modeling Instruction. I’ll take as much as possible from the AP Physics B course since most of it worked well the past two years. My AP Physics 2 students will also be piloting a 1:1 program (Chromebooks in the fall semester) which will require some additional preparation. AP Physics B is dead! Long live AP Physics 2!

AP Annual Conference: Making Sense of Electric Potential

Making Sense of Electric Potential

Jim Vander Weide, Hudsonville High School, MI

I attended this session since electric force, field, potential, and energy are concepts with which students struggle. I have attempted to make connections between these concepts and the corresponding gravitational concepts. I’m interested to see this teacher’s approach.

  • Jim provided slides building an extended analogy between gravitational fields and electric fields as well as other handouts. He would probably be willing to share, and his contact info can be found with a bit of Google-fu :)

AP Annual Conference: Results from AP Physics Exams

Results from AP Exams

Jiang Yu, Chief Reader

I attended this session to gain some insights into how the AP Physics B exam is scored and what common mistakes students made on the exam.

  • Question B1
    • 6.6/10
    • common errors
      • omit one of the three forces or add a normal force on FBD
      • use unconventional labels for their forces
      • units! students often omitted units
      • not recognize buoyancy is measured in Newtons
      • forces that appeared on the FBD often did not match the ones appeared in subsequent calculations
      • not using physics but general language in justification
  • Question B2
    • 6.0/15
    • common errors
      • applied kinematic equations for constantly accelerated motion to a motion of changing acceleration
      • not recognize that W=Fd can only be used when F is constant
      • not knowing that spring force is not a constant force
      • explanations are not concise and clear
  • Question B3
    • 3.6/10
    • common errors
      • non-linear scaling of axes in graphing
      • best-fit line often is drawn by just connecting points
      • not showing work for calculating slope of the best-fit line
      • not understanding that the light must pass from a higher index of refraction to a lower index of refraction in order to have total internal reflection
  • Question B4
    • 3.6/10
    • common errors
      • not reading the question carefully and not answering what is asked
      • not showing enough work beginning with the correct equations and then all the needed steps leading to an answer
      • messing up the horizontal and the vertical dimensions in calculations
      • deficiency in understanding the conservation of momentum
      • using “energy,” “force,” “momentum” and “velocity” interchangeable in explanations
  • Question B5
    • 3.6/10
    • common errors
      • misunderstanding of the sign conventions in evolved for heat, work and energy
      • not clear with their justifications, but often simply restated the question, and answer without providing further support
      • connected heat or average kinetic energy to temperature, but not to the internal energy
      • used W = -PΔV and did not discuss the effect of temperature on the pressure
  • Question 6
    • 3.5/15
    • common errors
      • simple calculations errors were everywhere
      • incorrect use or value of the magnetic permeability, μo, in Ampere’s Law
      • not understanding the intent of parts (a) & (b)
      • did not clearly understand the nature of the question and the connection of the parts to each other
  • Question 7
    • 2.7/10
    • common errors
      • the most common errors were the result of a lack of understanding of atomic states and associated energy levels. Students seemed to choose and use the equations without basic understanding of the physics involved.

AP Annual Conference: AP Physics 1 and 2 Courses

AP Physics 1 and 2 Courses

Connie Wells, Co-Chair, Physics 2 Development Committee

Karen Lionberger, College Board’s AP Program Director, Science Curriculum and Content

I attended this session to learn as much as possible about the new AP Physics 1 and 2 courses as we are “piloting” AP Physics 1 in the context of our Honors Physics course this upcoming school year.

  • Out of 1 million high school freshen interested in STEM majors and careers, 57.4% loose interest and switch to a different career path.
  • Big Ideas -> Enduring Understandings -> Essential Knowledge + Science Practices -> Learning Objectives
  • Physics 1 designed to have a couple of weeks of extra time to cover additional topics to meet requirements for state exams or teacher preference.
  • Big Idea 7 is only addressed in Physics 2. Some new material related to probability.
  • Rigor (or Vigor) = Complexity (and Autonomy) + Engagement
  • Teaching Strategies for Success in the AP Physics 1 and 2 Courses
    • assessment of prior knowledge, beliefs, and misconceptions that students bring with them to the course(s)
    • analysis of how to deal with students’ misconceptions
    • greater depth of conceptual understanding through the use of student-centered, inquiry-based instructional practices
    • use of formative assessments to guide instructional practices and provide feedback to students about depth of understanding
    • planning lessons based on the clearly articulated AP Physics learning objectives
    • integration of student inquiry laboratory work into the course
  • How the Learning Objectives Will Be Assessed
    • ability to solve problems mathematically – including symbolically – but with less emphasis on only mathematical routines used for solutions
    • questions relating to lab experience and analytical skills: designing and describing experiments; data and error analysis
    • questions asking for explanations, reasoning, or justification of answers
    • more emphasis on deeper understanding of foundational principles and concepts
    • interpreting and developing conceptual models
  • laboratory emphasis on students – inquiry-based, hands-on, integrated, investigative and collaborative
  • lab questions will focus more on error analysis and what the next step in the investigation would be
  • students will have to write at least one paragraph-length argument (make a claim and support with evidence) in the short-answer questions
  • 2014 professional development will launch new One-Day and AP Summer Institute Workshops to support the new courses
  • June 2014 – practice exams for both AP Physics 1 and Physics 2
  • sample syllabi available before March 2014
  • course and exam description (including equation sheets) available March 2014
  • course planning and pacing guides (8 total, 4 for each course)
  • teacher’s guide on inquiry-based investigations
  • 2 pacing guides will be available August 1st
  • Advances in AP site
  • 140 instruction hours is the target for AP courses (Physics 1 is targeted at 115-120 to allow time for additional topics)