This post has ended up a few days late. But I still have yet to miss an intended post on this blog!
Physics: Unbalanced Forces
Students did the classic Newton’s 2nd Law lab with a half-Atwoods machine, then we started fitting net force with the diagrams we’ve been working on. The first set of problems we typically do is just sketching diagrams. This year, we decided to try turning it into a card sort, which I think really helped students who were new to me transfer their knowledge of force diagrams into my classroom, something I’d been thinking about leading into the term. I also pushed using motion maps with acceleration arrows much harder than I have in the past, and one of the results was I got almost no questions this week about which direction the net force should be in.

AP Physics 1: Conservation of Momentum
We wrapped up the momentum transfer model (at least for now) by working on conservation of momentum. Students were very excited about Michael Lerner’s watermelon on wheels problem. Aside from being silly, I really like that it pushes students to play with viewing a single scenario with multiple different perspectives. We also did a little bit with momentum bar charts, since they show up in the AP Physics 1 workbook we did a few problems out of, and I found they really helped a lot of my students. I need to make much more use of those bar carts next year.