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.
This week was mostly about working problems for simple harmonic motion. I kept the focus on representations, including free-body diagrams, energy bar charts, and motion graphs, which made it a good review of a lot of mechanics topics. I also was really pleased when a student was checking out the topics we have left to cover on the AP Physics 1 Your Course at a Glance and asked if our unit on mechanical waves will have anything to do with the simple harmonic motion we’ve been working on.
Physics: Momentum Card Sort
This week, we worked on transitioning to calculations with conservation of momentum. We started with a collision lab from the Modeling Instruction curriculum, then did Kelly O’Shea’s momentum representations card sort. I’ve had a lot of students asking for me to do example problems before they work problems on paper, which I try to avoid. The card sort seemed to fill that need for a lot of students, while keeping the focus on their sense-making. I definitely want to work on a similar card sort for energy.
We worked on labs to determine what affects the period of objects in simple harmonic motion. I had half the class experiment with pendulums, while half the class used springs. During the board meeting, we did a lot of jumping back and forth between the two experiments; this lead to some good discussion about energy when we saw that mass mattered for the springs, but not for pendulums. I had each spring group use a spring with a different spring constant, which also lead to some good discussion about why the pendulum groups all got the same slope on their linearized graphs, while each spring group got a different slope.
Physics: Momentum Bar Charts
This week, we developed conservation with cart explosions, then worked on using momentum bar charts to represent conservation of momentum problems. After last week, I spent some time talking about the purpose of giving students time to work all (or most) of the problems on paper and warned them I would be unhelpful when they were preparing their whiteboards, then held to it. When we got to mistakes whiteboarding, I required groups to make at least one of their mistakes in the bar charts. While students were working on paper and preparing their whiteboards, I saw a lot more small-group discussion than usual, both within groups and across groups, which was fantastic. During the whole-class discussion, I also got some students speaking up who are usually pretty quiet and one of my classes even got some really good student-to-student exchanges, which have been very rare this year. On Friday’s quiz, students consistently felt really good about their performance. I’m hoping that the positive experience students had whiteboarding these problems coupled with good performance on the quiz will move the class culture in the right direction.
Students continued working on their final projects. One group is working on how the speed of a basketball affects the rebound of a backboard. They were working on some energy bar charts today and came up with some interesting notation; they labeled their kinetic energy blocks with “H” and “V” to keep track of how the components of the velocity were changing and how that fit with the energy.
Physics: Mirror Calculations Gallery Walk
Students did a gallery walk of yesterday’s problems. My sub from yesterday commented on how well they’d collaborated on the problems, so I was surprised that my students felt very lost on the problems. Once we started whiteboarding, it was clear they knew how to do the problems, but just weren’t confident yet.
I’ve also been randomly assigning groups almost every day, and I’ve come to enjoy the first few minutes of whiteboarding. Students immediately start comparing answers and approaches with the other people in their group and have lots of great conversation about similarities and differences in their work.
Chemistry Essentials: Nuclear Notation Gallery Walk
Students whiteboarded yesterday’s problems translating between different representations of an isotope for a gallery walk. Afterward, we started working on some problems writing out nuclear reactions for alpha and beta decay. I wish the decay problems started with some where the nucleus is reasonable to draw to help make identifying the products of the decay more concrete.
Students continued to work on their final projects. I have one group that’s interested in finding a way to measure the rate my Van de Graaff generator builds up charge. They spent some time today experimenting with ways to indirectly measure the charge.
Physics: Ray Diagram Mistake Whiteboarding
Students did some mistakes whiteboarding with ray diagrams for curved mirrors. Several students commented on mistakes they thought were especially helpful or interesting, which made me feel really good about the culture I try to build in my class. Students were also sad when they realized this will be their last round of mistakes whiteboarding in high school.
Chemistry Essentials: PhET Nuclear Structure
Students used PhET’s Build an Atom simulation to experiment with nuclear structure to kick of our nuclear chemistry unit. A lot of the information was a review from the first half of the course, but most needed a refresher.
Students continued work on their final projects. One group wants to figure out the charge vs. time function for my Van de Graaff generator. All three students in the group have different predictions for what that function will look like, which lead to some debates with lots of great thinking.
Physics: Ray Diagrams
Students finished working on some ray diagrams for curved mirrors and prepped whiteboards for some mistakes whiteboarding on Monday. Yesterday, a lot of students got frustrated when the rays didn’t meet perfectly or when they had to use virtual rays, but I think a lot of that resolved today.
As a quick refresher before today’s quiz, I gave students a fairly long worksheet, then had them pick out one example of each reaction type to put on a whiteboard. One student showed me how he’s been splitting the formulas in single replacement and double replacement reactions to relate back to general forms like AB + CD → AD + BC.
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 from The Cat in the Hat 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.
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.