**AP Physics 1: Uncertainty**

We did a quick preview of tomorrow’s lab on impulse, then talked about the challenges of finding the uncertainty of measurements given the tools we have so far. This lead into Brad Wysocki’s measurement lab to take a look at uncertainty caused primarily by your measuring tool. In my 2nd hour, I asked groups to find the area of some index cards using each ruler, but the size of the cards lined up too nicely with the rulers and the main points weren’t as clear as I’d like. In my 4th hour, I switched to Post-Its and the uncertainty was much clearer.

**Physics: CVPM Problems**

Students started working problems using CVPM. The problem set started with several descriptions of motion and students had to determine which statements CVPM could apply to. That was a more challenging task than I expected, largely because a lot of students were not clear about what I meant by CVPM, so I need to work on keeping that language clear. I also found my 1st hour, that mostly worked individually on the last problems, very easily shifted to working in groups today while a had a lot of students in my 6th hour opting to work alone, even though most of them went into groups on their own last time.

**Chemistry Essentials: Density Problems**

We started by discussing the results of yesterday’s lab. I ended up projecting some data I collected rather than making whiteboards. When we were talking about whether measuring a bigger dowel would give a different density, student comments revealed some of the class was interpreting data points on my graph as dots in a particle diagram. I’m really excited that my students are looking for connections between the different representations and are willing to share their thinking, even if we have some work to do on distinguishing between those representations.

Afterward, students worked on some problems relating particle diagrams, mass vs. volume graphs, and density. A lot of students had trouble getting started because they were struggling with the vocabulary; I pretty quickly wished I’d put together a short vocabulary activity to reinforce terms before we got to work.