This week was the start of a new trimester for us.
Physics: Vector Addition Diagrams
At the end of last trimester, we were working on balanced forces, but had only done situations where all of the forces were completely vertical or completely horizontal. This week, we started working with balanced forces where at least one is at an angle. This year, students have been struggling to relate different representations and see the connections between system schema, free-body diagrams, and vector addition diagrams, so I tried to keep my focus on supporting those connections. We started with some mini-practical stations I got from Kelly O’Shea to remind students of what we’d been working on before Thanksgiving break. When students asked for help, I made a point of emphasizing how the representations they’d drawn already to show how it lead to the next diagram. Next, we did an activity from Casey Rutherford where students used pipe cleaners to make the arrows from a free-body diagram, then physically rearrange them to make vector addition diagram, which I think helped solidify those connections. During the stations, I noticed that when there were multiple upward forces, a lot of students were drawing the arrows curved, which I think contributed to them struggling to connect the diagrams. Doing an activity where they were already given the free-body diagram and all of the arrows were perfectly straight seemed to help. We wrapped up the week with some paper and pencil problems relating free-body and vector addition diagrams (also from Kelly O’Shea). Students seem to be getting the hang of how these representations are related, and were starting to work on the next problems in their packet where we add in calculations before I assigned them, which was really exciting!
AP Physics 1: Impulse
Before finals, my AP students were working on impulse, but we ran out of time to assess it. This week, I decided to start by revisiting impulse and taking a quiz over it before we move on to conservation of momentum. We focused on some problems from the AP Physics 1 workbook, some of which included momentum bar charts. I usually skip over momentum bar charts, but my students seemed to find them really useful, so I think next year I want to make them more central to my momentum transfer unit.