# Day 134: Problems, Mistakes Whiteboarding, & PhET Limiting Reactants

I had a sub for half the day today, so only saw two of my sections.

AP Physics 1: Problems

Students worked on some problems with angular acceleration. I was at school for my smaller section, and the problems went very smoothly. They worked very independently and I overheard a lot of great discussion and connections to linear motion.

Physics: Mistakes Whiteboarding

I was at school for my only section, so we did some mistakes whiteboarding with Thursday’s problems. Students had some great mistakes and great discussion about the problems. One of the interesting things is when students were asked to sketch a v-t graph and divide it into sections, most groups did before, during, and after, mirroring the way we’d used velocity vs. time graphs during momentum transfer (inspired by Brian Frank). Asking them to tell me about what was happening to the box during each phase was pretty effective at shifting them.

Chemistry Essentials: PhET Limiting Reactants

I was gone for both sections of this class, so it was a great day for students to use PhET to introduce limiting reactants. My co-teacher sent me a message that the kids who got started got the ideas pretty quickly, but a lot had trouble getting started. The para who supports the class was also out today, so I think some students felt like they didn’t have the support they needed; I need to keep working on how to support my chem students in developing independence in the classroom.

# Day 133: Goal-less Problem, Forces Revisited, &

AP Physics 1: Goal-less Problem

We started with some mistakes whiteboarding of yesterday’s problems, which went very quickly and smoothly thanks to the connections my students were making to linear motion. Afterward, I gave them a goal-less problem for accelerated circular motion, and those connections continued to serve students well

Physics: Forces Revisited

We’d originally planned on taking a few days to close out the mechanics part of the course after oscillating springs, but the other physics teacher and I both forgot. Now that we’ve done what we’re going to with mechanical waves, we decided now would be a good time. Students worked on some problems revisiting the links between force, motion and other concepts from this year. There was lots of good discussion as they worked.

Chemistry Essentials: Gallery Walk

We did a gallery walk of some stoichiometry problems. Students have been doing well with the problems and seem to understand WHY they are doing the math they are, which I’m really excited about. I’m thinking about switching to BCA tables in the future; I need to spend some time trying problems with them. We’ll be starting work on some curriculum revisions for the course next year, and that might be a good time to take a closer look.

# Day 128: Problems, Tuning Forks, & Stoichiometry

I was on a field trip today, so had a sub.

AP Physics 1: Balanced TorqueÂ Problems

Students worked some problems with balanced torques. I wish I’d edited the worksheet to include some problems revisiting forces, but ran out of time last week. I’ll be interested to see if and how my students used the area model I showed them yesterday.

Physics: Tuning Forks

Students did a lab playing with tuning forks to start building some ideas about sound waves. There’s usually some good discussion that I’m a little sorry I missed.

Chemistry Essentials: Stoichiometry

Students started doing stoichiometry by using nuts, bolts, and washers to represent different types of atoms, making it possible for them to “see” how many moles they have and measure the masses very directly.

# Day 125: Assessment & Problems

AP Physics 1: Assessment

Students took their central net force quiz. Most seemed to feel pretty good about it, even though we moved through the content quickly.

Physics: Wave Problems

Students worked on problems using what we’ve learned this week. The problems went very smoothly.

Chemistry Essentials: Molar Mass Problems

Students worked on some problems combining molar mass with balancing chemical reactions.

# Day 72: Tests

Today was our last day of class before winter break. In all three of my classes, we wrapped up a topic by taking an assessment.

AP Physics 1: Energy Bar Charts & Unbalanced Forces

I’ve been giving students at least two in-class opportunities on every learning target this year, so this assessment covered energy bar charts and revisited unbalanced forces. Almost everyone improved on unbalanced forces, which is exactly what I want to see!

Physics: Conservation of Momentum

Students took their conservation of momentum test. Students have been saying the bar charts make the math very intuitive, and it definitely shows on the work I’ve graded so far. This is definitely the easiest time I’ve seen students have with momentum.

Chemistry Essentials: Density

This assessment was more hit or miss than my other classes. I had some students who did great, but a few were surprised to see some representations, like particle diagrams and a mass vs. volume graph, that were significant components of our daily work. I’m thinking about doing some individual conferences with students after break to try to get a better understanding of what’s behind that.

# Day 71: Unbalanced Forces Practical, Mistakes Whiteboarding, & Density Practical

AP Physics 1: Unbalanced Forces Practical

Since tomorrow’s assessment will include a second shot at our unbalanced forces learning target, we did a practical where students used unbalanced forces and constant acceleration to predict the velocity of a cart after it traveled a certain distance down a ramp. While we haven’t really dug into energy calculations yet, I did encourage students to try doing it as an energy problem if they had time, and the groups that tried it were excited to see the same answer two different ways.

Physics: Mistakes Whiteboarding

Students did mistakes whiteboarding to go over yesterday’s problems; not surprisingly, it went very quickly. I also didn’t have to get on students’ case about units or well-labeled diagrams, since they are at a point where they find it useful to see and were asking each other for that information when someone left it off.

I noticed a couple of groups in one section had started some interesting notation for their unknown I haven’t seen before; students really, really like to use x for their unknown, which I push back on, but these groups were using x plus a unit for their unknown. I can’t quite decide whether I like it; using x as an unknown does get in the way of using x to represent position, so I know I’d rather they use the standard variable. On the other hand, seeing the units written out for the unknown helped a lot of students see what math they needed to do and the students I talked to were very clear that “x m/s” represented how many meters the object traveled for every second, which the students just using v were not as consistently clear about. I’m trying to decide whether the potential value here outweighs the hurdles it may cause down the line; one option is to let them leave the units, but push they should still use the standard variable (like “v m/s” here). I don’t see myself ever introducing this kind of notation, but I’m also not sure I need to get students away from it if they find it useful.

Chemistry Essentials: Density Practical

As a practical to wrap up the density unit, I asked students to plan an experiment they could use to answer either whether the shape of an object impacts its density or whether the volume of an object impacts its density. It went about as I expected; initially, students were uncomfortable with how open-ended the task was, but, once they got started, they moved forward easily with the task. I think the challenge had more to do with students’ discomfort with this kind of task than their ability to complete it.

# Day 61: Mistakes Whiteboarding, Impulse Problems, & Designing Experiments

AP Physics 1: Mistakes Whiteboarding

Students did some mistakes whiteboarding with yesterday’s problems. A few students said they feel like unbalanced forces are easier than balanced, which I made sure to point out is a great indicator of how much they’ve grown in using free-body diagrams and vector addition diagrams.

Physics: Impulse Problems

Students worked on some problems using yesterday’s results on impulse. Overall, the problems seemed to go well, but I need to think about how to handle whiteboarding. I’ve got one section of 30, where I’ll be able to handle whiteboarding the way I normally would. My other section is only 8 students, and they ended up gathered around a single table having a lot of great discussion about how to do the problems. I’m not sure how much a whiteboarding session will add to their understanding.

Chemistry Essentials: Designing Experiments

We spent some time talking about the graphs I made of yesterday’s lab results, then moved on to starting the next set of mass and change labs. I asked students to plan their own procedure for finding the change in mass for sugar dissolving in water and Alka-seltzer dissolving in water. This turned out to be harder than I expected, so we ended with some whole-class discussion to figure out what steps we needed and why.