Days 89-92: Waves & Momentum Practical

We had a four-day student week for a professional development day on Friday.

AP Physics 1: Waves

This week week we worked on developing and using the wave equation, as well as a few other concepts on mechanical waves. We started with a standing wave lab in Pivot Interactives. On a few labs this year, students haven’t taken the time to get good quality data, which has made it tough to make sense of the slopes during the board meeting. As students are getting better at constructing new ideas from lab results, they are starting to really see the value in having good results to discuss and this lab was a place I saw it really pay off. Students worked through linearizing their graphs and figuring out units of their slope with very little intervention from me partly because they knew those steps would help their sense-making and partly because they are getting more skilled and need less support. Every group had beautiful data for the board meeting and, as we worked on problems later in the week, I heard a lot of students referring back to their graphs or their qualitative observations to think through a problem. All around, this was a really fun week to watch and listen to my students.

Physics: Momentum Transfer Practical

Students worked on applying conservation of momentum to problems, including a lab practical. For the practical, students had to determine an unknown mass using photogates and a dynamics track. The groups that were able to sketch momentum bar charts that matched the collision they decided to do were typically able to find their mass pretty quickly, but a lot of students struggled to connect their bar charts to what was happening on their lab table. As we move into energy, I need to think about how I’m going to make sure students are connecting representations like bar charts to things they can observe or interact with in the lab and beyond. I did enjoy seeing the different approaches groups took to the practical. One based their approach on cart explosion lab and added mass to their empty cart until both carts had the same velocity after the explosion.

Days 68-72: Energy Practical & Pushing Boxes

AP Physics 1: Energy Practical

This week, students worked on applying conservation of energy. We wrapped it up with a lab practical to find the spring constant of a popper toy. To help with what makes a good procedure, I had groups start by writing out the steps they were going to follow on a whiteboard. Then, they traded whiteboards with another group and had to follow the procedure they were given to actually collect data. One group came up with a nice strategy of writing out the equation they’d use in their calculations, then checking off each variable as they added a step to measure it.

Physics: Pushing Boxes

Students spent a lot of time this week on problems applying Newton’s 3rd Law and synthesizing Newton’s Laws, including some great problems originally from Matt Greenwolfe where students draw free-body diagrams and velocity vs. time graphs for boxes pushed across various floors. While there was some great discussion, I think these problems would have been more valuable much earlier in the forces model. In general, I think Newton’s 3rd Law feels like an afterthought in how we approach forces. With some shifts in what we’re doing early in this model, we could better integrate key elements of this model and reduce the need for doing some kind of synthesis at this point in the unit.

Days 32-35: Newton’s 3rd Law & Newton’s 1st Law

This was another short week. Parent-teacher conferences were on Thursday night, so Friday was scheduled as a professional development day.

AP Physics 1: Newton’s 3rd Law

This week our focus was on Newton’s 3rd Law. Students predicted which cart would experience a larger force during various collisions, which we then tested using a pair of carts with force sensors and hoop springs. In my grad class this semester, we’ve been doing a lot of talking about the ways language students use can mask meaningful understanding, which got me thinking about how I can make better use of students’ predictions. This year, I tried being very explicit that our task was to find the useful ideas in students’ predictions and to translate those useful ideas into the language physicists use. There was a great moment where a student said “So the force and the result of the force are different things, but we were treating them as the same”, which I couldn’t have planned better.

I also took a page from Brian Frank this week and used some magnetic hooks for an easy setup of a static forces lab practical.

Find the unknown mass using the spring scale readings, a protractor, and a ruler.

Physics: Newton’s 1st Law

This week was about developing the idea of a force and Newton’s 1st Law using interaction stations and the bowling ball lab. A few students were resistant to actually trying the bowling ball lab this year, rather than actually testing whether what they expected worked, so I had to push some groups to really explore getting the bowling ball moving with a constant speed. Once they got started, however, there was some great discussion.

Made in Motion Shot

Days 29-31: Vector Addition Diagrams & CAPM Practical

This was a three-day week since public schools closed on Thursday and Friday for the state teachers union conference.

AP Physics 1: Vector Addition Diagrams

Students started the week by doing Kelly O’Shea’s forces representations card sort. I used the card sort to introduce vector addition diagrams, and students easily recognized key aspects of the VAD. The rest of the week, we worked on applying VADs to solve problems. They are successfully applying the VADs, but aren’t feeling confident in their skills just yet.

A completed forces representations card sort categorized into balanced and unbalanced forces.

Physics: CAPM Practical

After wrapping up some problems using the constant acceleration model, students started working on a practical to figure out where to start a marble on a ramp so that it lands in a passing buggy. We ran out of time for students to test their calculations. While students made good progress, many are uncertain of their skills; I’m hoping that completing the practical on Monday will help them build confidence.

Days 15-19: Interaction Stations & Constant Velocity Problems

AP Physics 1: AP Workbook

To wrap up constant acceleration calculations, we worked on some problems out of the College Board’s workbook. There was a lot of great discussion as students worked through the relatively complex problems. Students have been nervous about the early registration date for the exam this year, and working the problems seemed to help alleviate some of their fears.

Students also worked through an activity based on Brian Frank’s interaction stations to start building their model of a force. I had a sub that day, so afterward had students use a reading to define the major types of forces we’ll be using in class and connect them to the stations. We’ll be discussing the stations early next week and I’m thinking about how I want to approach the discussion. This week, I happened to read a chapter from Bryan Brown’s Science in the City where he talks about how teachers often miss how accurate students’ preconceptions are because students aren’t ready to express those ideas in scientific terms. I’m wondering how I might change the way I usually approach this discussion (and many others) to do a better job of recognizing and building on what students knowledge, regardless of the language they use to express it.

Physics: Constant Velocity Problems

Students worked problems, including the dueling buggies practical, using the constant velocity of a particle model. On their weekly reflection, a lot of students wrote about navigating different ideas within their groups about how to complete the lab practical. I was really excited to see that multiple approaches were suggested in most groups and that students were thoughtful about how to balance making everyone heard with moving forward as a group.

We also did some mistakes whiteboarding. In both my courses, I’ve been pleasantly surprised by how quickly students are buying in to this activity. My Physics students have been pretty quiet during the whole-class discussions, but they are consistently referencing it in reflections as something they find helpful for learning and where they feel proud of their work in class.

Days 10-14: Constant Acceleration Representations & Constant Velocity Calculations

AP Physics 1: Constant Acceleration Representations

We spent this week working on getting representations for constant acceleration down. I made quite a bit of use of Brian Frank’s magnetic vector manipulatives during class discussions of motion maps. I think it would be worthwhile to make a set for each lab group; I don’t have magnetic surfaces at my lab stations, but I think the laminated arrows would still be useful to students while they’re working.

I’ve been doing more work on collaboration so far this year, and I’m seeing it pay off with students seeking out input from a greater variety of people when they’re stuck and with ideas jumping between groups much more than in the past. I especially love when students start working problems with one group, then whiteboard with different people and begin by comparing approaches.

motion map.jpg

Physics: Constant Velocity Calculations

Students worked on applying the constant velocity of a particle model to calculations, including predicting where two buggies will collide. One challenge, which has come up the past few years, is a lot of students are having trouble connecting the calculations to the representations we’ve been using. I think there’s a couple of things going on. In a lot of classes, once students have taken an assessment, they no longer need to use those skills, so I think some students feel like they are done with constant velocity representations after last week’s quiz. I think the other hurdle is some students, especially those less confident in math, are looking for things they can memorize to bypass the sense-making involved in sketching the diagrams. I haven’t figured out good strategies to help students work through these hurdles aside from coaching individuals and small groups on doing the sense-making and sketching the diagrams when they are stuck. I also need to keep reminding myself that as the year goes on, more will get on board with continuing to use skills we’ve assessed and working through the sense-making steps.

Day 152: Final Projects, Board Meeting, & Activity Series Practical

AP Physics 1: Final Projects

Final project proposals are due tomorrow, so students worked on finalizing their topic. I got to have a lot of fun conversations today to help students narrow down their topic. One student had picked out a clip fromĀ The Cat in the HatĀ but wasn’t sure what she wanted to do with it, so we spent some time talking about the physics involved.

Physics: Curved Mirror Board Meeting

We whiteboarded the results of yesterday’s lab to get to the mirror equation.

curved mirror board.jpg

Chemistry Essentials: Activity Series Practical

Students got a pre-1982 penny and a post-1982 penny, each with a wedge cut to expose the insides, and used an activity series to predict which would react with hydrochloric acid.

pennies in hcl.jpg