AP Physics: Exploding Carts

Today’s quiz took longer than I expected. One of my classes had some time to start collecting data on two carts in a mechanical explosion. They are plotting the ratio of the cart masses to the ratio of their speeds after a spring-loaded plunger launches them apart. I thought about using some probeware to measure the velocity, but went low-tech and had them use the ratio of the distances when the carts reached the end simultaneously. I like that this approach encourages students to start looking for patterns as they collect their data.

Physical Science: Sound

Students used tuning forks and wine glasses to explore some ideas about sound. Students made a lot of great observations and had good discussions with their lab groups and were able to bring some of that back to the whole-class discussion. One of the instructional coaches came by to give some input on helping my students adjust to my approach, and he had a couple of ideas I want to try. Since I keep relationships very qualitative in 9th grade, I ask a lot of questions with limited options, such as whether a variable increases, decreases, or stays the same when another variable changes. The coach suggested I have students physically move to a specific part of the room based on their answer to make it harder to opt out and to facilitate some additional conversations between students. I also like this because it is more obvious to students that we’re doing something different than going over answers like they’re used to. I tend to skip whiteboards in 9th grade, but my conversation with the coach has me thinking they would have some of the same benefits. I need to give some thought to how I can make time for whiteboards in a very tight curriculum.

I also got an idea from grading notebooks this afternoon. I use interactive notebooks, but have gotten very lazy about doing the left side/right side stuff. One of my students has started having a page for each lab, then using the facing page for a summary of the big ideas. That was a good reminder that the left side/right side can actually fit pretty well with what I’m trying to do in the class and I should be having students do those lab summaries.