# Day 94: Whiteboarding, Bouncy Ball Energy, & Classifying Matter

AP Physics: Whiteboarding

Students whiteboarded their answers to yesterday’s problems. There were a couple of meaty ones on the worksheet, so I had all groups whiteboard the same problem and then we had several consensus-building conversations.

A visual for quantization of charge

Physics: Bouncy Ball Energy

We wrapped up figuring out where a bouncy ball dissipates energy. As part of the follow-up, we dropped a kickball under a motion detector (thanks to Brian Frank for the idea!) to produce energy vs. time graphs and confirm the results from students’ video analysis.

Chemistry Essentials: Classifying Matter

Students worked on a worksheet to connect particle diagrams to the vocabulary for classifying matter that we introduced yesterday. I also was able to have really good individual interactions with a couple of students I’ve been butting heads with a lot, which helped make the whole classroom feel more relaxed and positive. I’ve been getting overwhelmed in chemistry a lot this year and have not done a good job of making time to talk to students about things besides chem, and I can’t underestimate the value of those conversations.

# Day 93: Coulomb’s Law, Dissipated Energy, & Compounds

AP Physics: Coulomb’s Law

Students worked on some problems using Coulomb’s Law. I was surprised at how challenging a lot of students found a problem that deals with the quantization of charge, but there were a lot of great conversations as students worked through that one.

Physics: Dissipated Energy

We moved into the video analysis portion of determining where a bouncy ball dissipates energy (my article about this activity was published in the January issue of The Science Teacher). Before they got their bouncy ball, groups had to tell me what specific measurements they would use from the video analysis; the groups that completed the worksheet from the past few days were very successful while the groups that left big portions of the worksheet blank really struggled. I had one group get really excited watching their video when they noticed the bouncy ball got less blurry at the top of each bounce since it showed the bouncy ball really does briefly stop at the top.

Chemistry Essentials: Compounds
Students observed iron and sulfur, eventually heating it in a test tube to make iron sulfide. They were very into burning the iron and sulfur. Afterward, I used their observations in the lab to introduce vocab for pure substances, mixtures, and compounds.

# Day 92: Board Meeting, Dissipated Energy, & Mistakes Game

AP Physics: Board Meeting
Students whiteboarded their results from a Pivot Interactives activity on Coulomb’s Law. There was some debate over whether inverse or inverse-square was the right linearization; I usually don’t have students sketch their points on their whiteboards, but I think that would have been helpful today. Students did a nice job connecting their results to Newton’s Laws and their knowledge from chemistry.

This group ran out of space for their linearization, but I found their set of graphs very satisfying.

Physics: Dissipated Energy

We continued prep for determining which interaction causes a bouncy ball to dissipate energy (my article about this activity was published in the January issue of The Science Teacher) by whiteboarding key points of yesterday’s work. Today really seemed to help a lot of students see the connections between the energy bar charts, free-body diagrams, and velocity vs. time graphs, which is exactly what I was going for.

Chemistry Essentials: Mistakes Game

We used the mistakes game to go over yesterday’s problems. There was some great discussion, but it was very tough to keep students from breaking into side conversations. Next time, I should spend a little more time making sure behavior expectations are explicit as possible and helping students see the value in those expectations. There were also some students who were extremely engaged and clearly developed a lot of confidence in sketching Borh models today, which was awesome.

# Day 91: Coulomb’s Law, Bouncy Balls, & Bohr Model

AP Physics: Coulomb’s Law

Students worked on a Pivot Interactives activity to find a relationship between the force between two charged spheres and the distance between them. A few students started wondering about the limits of the model since they recognized an infinite force doesn’t make sense, which lead to some good discussion about what it would take to make the distance zero.

Physics: Bouncy Balls

Students started working a lab to determine what interaction is dissipating energy for a bouncy ball (my article about this activity was published in the January issue of The Science Teacher). Today, students worked on sketching representations of the bouncy ball’s motion, including energy bar charts, free-body diagrams, and velocity vs. time graphs for each possible explanation in order to identify useful evidence they can get from video analysis of the bouncy ball. To scaffold this process, I had students sketch the representations on a worksheet today rather than going straight to whiteboards.

Chemistry Essentials: Bohr Model

We talked about the results of last week’s simulation to find the links between the Bohr model and the periodic table, then students worked on a worksheet sketching Bohr models from the periodic table. I skipped over revisiting static electricity (which the Modeling Chemistry curriculum calls for) to help establish the concept of charge, but I think next time I’d like to make time for it.

# Day 136: Electrostatics & Permeability

AP Physics: Electrostatics

I missed class for a field trip today, but the rest of this week is all about squeezing in superficial coverage of the last few topics. Today, students worked some problems I wrote to refresh their memory on some electrostatics from chemistry, then help them reason their way to what they need for physics. There are no classes tomorrow, so I’ll find out Thursday how it went.

Earth Science: Permeability

Students whiteboarded yesterday’s lab results, then we did a quick demo on permeability. Then students used what they’ve learned to design an aquifer.

# Day 67: Projectiles With v-t Graphs & Static Electricity

AP Physics: Projectiles With v-t Graphs

Students took their first crack at projectiles launched at an angle. As with the rest of motion, I’m having them solve from velocity vs. time graphs, rather than the typical equations. I’ve had a number of students tell me they feel like this topic is easier than acceleration, which is a nice opportunity to show students the progress they’ve made so far this year.

Physical Science: Static Electricity

Students did their first lab on static electricity today. I modified a lab from Eugenia Etkina’s PUM curriculum to make use of the static electricity kits we have. Most of the tests involved hanging a rubber rod from a string, so students had some trouble telling whether the rod was spinning due to static forces or due to tension in the string. Students pretty quickly figured out they could check by trying to repel the hanging rod in the opposite direction, they made some good observations. It was also tough to build up really big charges on the rods, so I might consider switching the equipment next year.

# Day 75: Coulomb’s Law & Mystery Tube

Physics: Coulomb’s Law

Students worked a few problems using Coulomb’s Law. I was really pleased to see how smoothly students integrated what they’d learned about Newton’s Laws back in November with the new concept. Something about today lead several students to say they feel like they finally understand how to learn physics, which was great to hear.

Chemistry: Mystery Tubes

After this week’s lab, I wanted to spend some time on observations, inferences, and the nature of science. We talked a bit about the difference between observations and inferences, and what makes a good example of each, then asked them to make some observations and inferences about a few photographs. A photo of a crying baby lead to some great discussion when I started to list the crying under observations and several students disagreed and proposed some other explanations for the baby’s facial expression. I love it when students are confident enough in their ideas and comfortable enough in the classroom to challenge me. After the photos, I got out a pair of “Mystery Tubes” and asked students to try to come up with some inferences about what’s inside the tube, then use toilet paper tubes and string to test their inferences. There was some great discussion as students proposed ideas, then challenged what their peers were thinking, always talking about the evidence they have. Going forward, the challenge will be to make sure students are bringing those same skills and enthusiasm to more standard chemistry labs.

# Day 74: Board Meeting & Observations

Physics: Coulomb’s Law Board Meeting

Students whiteboarded the results of yesterday’s lab and we had a board meeting. I had students graph force vs. distance, then both an inverse and inverse-square test plot so we could compare the correlation coefficients. While both classes were able to get to the inverse-square relationship, I struggled to get students to take the lead in the discussion. I think part of the problem is, while we’ve whiteboarded lots of problems and conceptual questions, the last board meeting where we focused on graphs produced in a lab was early November. I need to either do more whiteboarding labs during projectile motion and energy, or I need to bring in more of the scaffolding I do early in the year to help students refresh their skills.

Chemistry: Observations of Reaction Types

Students finished up the lab from yesterday, then we spent some time trying to connect their inferences to their observations in the lab. In the discussion, I realized I need to make explicit to my students what is a good observation and how that contrasts with an inference or claim. For example, the textbook lists gas formation as a sign of a chemical reaction, so nearly every student listed gas formation as an observation at least once, but struggled to explain what they saw that suggested a gas was formed. I can’t forgot how important it is to explicitly address the basics in a class like this.

# Day 73: Coulomb’s Law & Reaction Types Lab

Physics: Coulomb’s Law

Students used fur to charge a pair of balloons hanging from a meter stick, then measured the angle the strings were at as a proxy for the force. They then collected data to find a relationship between the force the balloons exert on each other and the distance they are separated.

Chemistry: Reaction Types Lab

I borrowed a lab from the Modeling Instruction chemistry curriculum where students actually carried out reactions of each type, and  made some observations to connect the reaction equation to what actually happened in the lab.

# Day 72: Van de Graaff & Finish Review

Physics: Van de Graaff

We started by discussing the results of yesterday’s lab. It ended up much more teacher-centered than I would have liked; I had a few different concepts I wanted students to take away from the lab, and I wasn’t quite sure how to have students summarize their results on a whiteboard or how to guide the discussion to get students to those concepts. It also didn’t help that about half of my students were on a field trip and the empty room made students more self-conscious about speaking up. After discussing the lab, we played with the Van de Graaff generator. Students did a nice job of using what they’d gotten from the lab to make predictions and construct explanations of what we saw with the generator.

Chemistry: Finish Review

No one managed to finish yesterday’s assignment, so we spent some time discussing together the parts students had finished, then I gave them time to finish the rest. I’d hoped to start a lab today, but many students needed the whole hour to work.