Days 103-106: Kirchoff’s Laws & Energy Card Sort

AP Physics 1: Kirchoff’s Laws

Students worked on developing Kirchoff’s Laws this week. We started with PhET’s circuit construction kit, then got out the power supplies and resistors. Some groups had trouble recognizing the simulation and the physical lab as addressing the same concepts, but explicitly asking groups how their results compared seemed to help students make the connections. There was also some good discussion about why the results in the physical lab didn’t match the simulation exactly. A thermal photo showed some heat at the alligator clips, which lead to some conversation about whether the wires we were using were ideal.

Physics: Energy Transfer Card Sort

This week we worked on starting energy conservation problems. To help the transition from bar charts to problems, I turned some problems Kelly O’Shea and Mark Schober wrote for the New Visions physics curriculum into a card sort. Seeing cards with two versions of the conservation of energy equation seemed to help a lot of students see how to build equations from the bar charts, which made the problems much smoother than in the past.

Days 98-102: Circuits Intro & Energy Bar Charts

AP Physics 1: Circuits Intro

We used PhET’s circuit construction kit to introduce some circuit basics and develop Ohm’s Law. Afterward, we used nichrome wire to test how the length of a wire affects its resistance. The data came out great, with groups that used thinner gauges of wire consistently getting larger slopes than groups who used thicker gauges. I usually skip over resistivity, but, at the AP reading last year, Wayne Mullins shared how he uses resistivity as a conceptual basis for Kirchoff’s Laws and I’m really excited to try that approach with my students this year.

Physics: Energy Bar Charts

This week was all about switching over to energy bar charts. I also noticed students are getting much more vocal during whiteboard sessions. I can’t figure out what’s behind it, but I’m really enjoying it. We’re getting close to the end of the trimester, and a lot of students switch between hours (or even between teachers), so I’m starting to think about how I can help students maintain this progress at the transition.

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 63-67: LOL Diagrams & Newton’s 3rd Law

AP Physics 1: LOL Diagrams

Students worked on sketching bar charts and LOL diagrams to show energy transfers. I was really pleased with how comfortable students were switching between different systems. I started out the week by having students use a spring scale to pull a cart up different ramps, always raising their cart to the same height above the table. We then sketched force vs. displacement graphs to introduce the idea of work and gravitational potential energy. Getting both simultaneously meant the concepts blurred together for students at first, but that issue got resolved as we did mistakes whiteboarding with energy bar charts and LOL diagrams.

Physics: Newton’s 3rd Law

One of our major tasks this week was developing Newton’s 3rd Law. Students started by predicting how the forces on two colliding carts would compare, then we tested out the collisions. As we tested the collisions, I cued students to notice the relative accelerations of the carts, which I think helped students see the useful thinking in their original predictions. Before we officially stated Newton’s 3rd Law, I borrowed an idea from Mark Schober and had students play with film canisters with magnets inside to test and refine their rule before the whole-class discussion.

Day 92: Board Meeting, Representing Free Fall, & 2 Truths and a Lie

AP Physics 1: Pendulum Board Meeting

Students whiteboarded their results from yesterday’s pendulum lab. For mass and release angle, there were a couple of groups who sketched graphs that did not start at zero, which was great for having some discussion about why the scale of your graph matters. This was also the first graph students had that wasn’t quadratic or linear, so no groups linearized initially and we had some fantastic conversation about the intercept, which actually started in some groups while they were still prepping whiteboards. By the end of the hour, every group had linearized and was on-board with a square root relationship.

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Physics: Representing Free Fall

Students used some questions I modified from Michael Lerner to represent a falling orange using tools from each model we’ve covered so far this year. By the end of the hour, students commenting that free fall and projectile motion really aren’t anything new, which was exactly the goal! Students were struggling to connect this activity to the graphs we discussed yesterday, so that will be something to work on tomorrow.

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Chemistry Essentials: Periodic Table 2 Truths & a Lie

After discussing some of the trends in the periodic table, we did some whiteboarding to practice reading the periodic table and recognizing the trends. Since there isn’t a whole lot of depth to the questions I could ask at this point, each group prepped a whiteboard with two correct statements and one incorrect statement. Then, they traded whiteboards with another group who had to find and correct the wrong statement.

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Day 87: Projectile Practical, Energy Problems, & Board Meeting

AP Physics 1: Projectile Practical

Students finished predicting where a marble rolled off a lab table will hit the floor. Once students have a success, I gave them a lighter marble and asked them to predict where it will land without taking any new measurements.

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Physics: Energy Problems

Students worked on calculations using conservation of energy. This was a tougher leap than I expected given how easily students got the hang of setting up conservation of momentum problems from bar charts. I think a card sort similar to the one we did for momentum would have been a good stepping stone.

Chemistry Essentials: Board Meeting

Students had a board meeting with their results from yesterday’s lauric acid lab. I had students collect data for the acid both melting and freezing, which made for a good visual of how similar those processes are. Students also made some good connections to last week’s activity in Pivot Interactives. I think starting with the cleaner data helped students to see the patterns in their data and there was some great conversation about why everyone had the same temperatures on their flat sections today while different groups got different temperatures on their graphs last week.

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Day 85: Whiteboarding, Video Analysis, & Board Meeting

AP Physics 1: Whiteboarding

Students whiteboarding yesterday’s problems. I focused on a consensus-building approach, where all groups whiteboarded the same problem, then we used the discussion to come to an agreement on what the answer should be, and why. Both my sections have a pretty good sense of class community, which made students pretty comfortable sharing work they weren’t sure about yet and building off each others’ ideas.

Physics: Video Analysis

We finally got out the computers to do some video analysis of a bouncy ball to figure out what interaction is dissipating the energy. I’ve never had much luck walking the whole class through the software, so I have a video analysis guide with lots of animated screenshots that I put on the class website. Students were able to get some nice graphs of the bouncy ball’s motion and connect them to our work from the past few days.

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Chemistry Essentials: Board Meeting

Students whiteboarded their results from yesterday’s lab in Pivot Interactives. During the board meeting, students continued to share observations faster than I could write them down, which is a great problem to have in this course. It was also very clear to students that the temperature stays fairly constant during the freezing process. I’m hoping having had a board on these results will help students make sense of our lauric acid lab on Tuesday.

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