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

December 20, 2018December 20, 2018 / Marta R. Stoeckel / Leave a comment

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 70: Systems and Bar Charts, Conservation of Momentum Problems, & Pivot Interactives

December 19, 2018 / Marta R. Stoeckel / Leave a comment

AP Physics 1: Systems and Bar Charts

Students worked on whiteboarding some problems switching between different systems for energy bar charts. Students were doing a nice job of switching smoothly between different systems.

ap bar chart

Physics: Conservation of Momentum Problems

Students worked on calculations with conservation of momentum. This is the first year I’ve really used momentum bar charts, and its also the first time I’ve had students call conservation of momentum easy. The best part was I overheard a lot of students talking about whether their answer was reasonable based on their bar charts. When one of my AP sections came in, I still had some bar charts on the whiteboard and my AP students asked why I didn’t teach them momentum bar charts since it made the problem seem much easier. I’m sold and will be bringing bar charts into AP next year.

Chemistry Essentials: Pivot Interactives Density

I am as part of Pivot Interactive’s Chemistry Fellows program.

Students worked on an activity in Pivot Interactives to identify materials based on their density. I ended up giving students a handout to record their work, rather than having them answer in Pivot’s interface, since something about writing on paper seems to feel more comfortable for a lot of my students. I was really excited about how many students on their own tried to decide between multiple materials with similar densities by paying attention to what they could see about the material. It was also nice to be able to easily split up the class to look at different liquids so we can have some conversation tomorrow about who should have similar answers and who should have different answers, and why.

pivot density.PNG

Day 69: Mistakes Whiteboarding & Card Sort

December 18, 2018December 18, 2018 / Marta R. Stoeckel / 1 Comment

AP Physics 1: Energy Bar Chart Mistakes Whiteboarding

Students did mistakes whiteboarding with energy bar charts. There was some good discussion about what differences matter in energy bar charts at this point and what differences, like the exact number of boxes, are irrelevant.

Physics: Momentum Card Sort

Students worked on a momentum transfer model card sort I got from Kelly O’Shea. I was (pleasantly) surprised by how easy it was for students to work out which equation went with each problem. The force-time graphs in the card sort were tough; part of the trick is those graphs are more similar across different problems than some of the other graphs and we haven’t made enough use of force-time graphs in other contexts for students to focus on the subtle details that distinguished the different graphs here.

Chemistry Essentials: Density Mistakes Whiteboarding

This class also did mistakes whiteboarding, but on a worksheet using different representations for density. There was some great discussion and some signs this group is starting to build an identity as a class, which is great.

Day 68: Energy Bar Charts, Momentum Bar Charts, & Density Problems

December 17, 2018 / Marta R. Stoeckel / Leave a comment

AP Physics 1: Energy Bar Charts

I introduced students to LOL diagrams and had them start working on some energy bar charts. Things seemed to go very smoothly. I have one section that is very small this tri, and I need to be conscious of how quick I am to jump in when students are stuck or have a question. In a larger class, I have an easier time leaving more space for students to think and discuss with each other since I hear less of the conversation and feel more pressure to move between groups.

Physics: Momentum Bar Charts

Students did some whiteboarding to wrap up momentum bar charts before taking a quiz. In my larger class, I tried representation jeopardy. This hour didn’t like it as much as my small class; students said they would prefer something that is structured more similar to the types of problems that show up on assessments. I’m not overly surprised, since many of my students are still much more comfortable with answer-getting than meaning-making, but I need to keep thinking about how my moves in the classroom place value on each approach to physics and how I can shift what I’m doing to place more explicit value on meaning-making.

Chemistry Essentials: Density Problems

Students worked on a worksheet connecting particle diagrams to density. I gave less instruction than I typically do, which lead to more student-to-student conversation and more student success than I’ve seen on this worksheet before. I get frustrated and push back when someone says “those kids” can’t handle reform-based science instruction, I’m still susceptible to that line of thinking and sometimes over-scaffold. When I give them space, the students I have in Chemistry Essentials can rise to the occasion just as well as the students I get in other courses.

Day 67: Board Meeting, Representations Jeopardy, & Density of a Solid

December 14, 2018 / Marta R. Stoeckel / 1 Comment

AP Physics 1: Board Meeting

Students whiteboarded their results for the elastic potential energy lab we’d done earlier this week.

Physics: Representations Jeopardy

In both my sections, we started with mistakes whiteboarding for yesterday’s problems. My 6th hour is about 1/3 the size of my other section, so they got through the mistakes whiteboarding very quickly. I tried what I called Representations Jeopardy: each group came up with a scenario, and whiteobarded a set of representations, minus the sketches and any labels that would identify what the objects involved are. Then, groups traded whiteboards and had to come up with a scenario that matched the whiteboard they received. Students said they really liked that they had to think differently in order to work backwards from the diagrams.

From mistakes whiteboarding

Chemistry Essentials: Density of a Solid

Students worked on finding the density of some metal dowels. I realized belatedly this is the first lab we’ve done where they didn’t need a container when measuring the mass, so it was actually a tricky leap for them to not tare something out on the balance.

Day 66: Board Meeting, Momentum Representations, & Density

December 13, 2018December 13, 2018 / Marta R. Stoeckel / 1 Comment

AP Physics 1: Kinetic Energy Board Meeting

I am being compensated by Pivot Interactives as part of their Chemistry Fellows program.

Students whiteboarded their results from this week’s Pivot Interactives activity with a puck on a ramp to get to a definition for kinetic energy. I definitely wish I’d done energy bar charts prior to this lab, but conservation of energy is emphasized enough across our science curriculum that it wasn’t too big of a leap for students to recognize the energy transformation happening. Students were really pleased when they realized their slope worked out to equal 1/(2g), which is exactly what the formulas predict.

Physics: Momentum Representations

Students worked on representing momentum transfer using sketches, bar charts, and velocity vs. time graphs. The use of velocity vs. time graphs was influenced by Brian Frank’s work on momentum representations, and I really like the way it connects momentum to tools we’ve used earlier in the year. I’ve got one section with 30 students and one section with 8, and I’m quickly figuring out I need to be conscious about hanging back in my small class to encourage them to talk to each other about the problems before they talk to me.

Chemistry Essentials: Density

Students worked on finding a relationship between the mass and volume of water. Today really stretched my students since I had them design their own experiment and we started a board meeting on the lab, but students rose to the challenge. I’ve been having them use fill int he blank “for every” statements to talk about their slope, and that has been a big help for students to get a conceptual understanding of what their slope means. Yesterday, we had to pause the board meeting to define what the intercept of a graph is, so I got really excited when students not only brought up that groups had intercepts of either 0 g or 10 g, but came up with the idea that the intercept came down to whether groups hit tare after putting their graduated cylinder on the balance.

Day 65: Spring Energy & Board Meetings

December 12, 2018 / Marta R. Stoeckel / 2 Comments

AP Physics 1: Spring Energy

I am being compensated by Pivot Interactives as part of their Chemistry Fellows program.

Students collected data for a relationship between a spring’s stretch and the final velocity of an attached cart using a lab in Pivot Interactives. While I took more time than yesterday on a pre-lab discussion, I think students were still a little confused since we haven’t talked much about energy types yet. I think it would have helped if we’d done the board meeting for yesterday’s lab prior to this activity. I’m also thinking about doing bar charts before these equations next time around.

Physics: Explosions Board Meeting

Students whiteboarded their results from yesterday’s lab to introduce conservation of momentum. This was a tricky discussion for a lot of my students since we were dealing with four variables simultaneously, but students did well with it. It was a nice reminder of the progress my students have made so far this year.

Chemistry Essentials: Volume Board Meeting

Students whiteboarded their results from yesterday’s lab. I really hit “for every” statements about the slope hard, and that seemed to help students attach some conceptual meaning to the slope. There were a few groups who graphed the actual water level, rather than the water displaced, which gave a great opportunity to talk about what the intercept tells us in this lab. I think next time, I’ll make sure a couple of groups do that.

Day 64: Kinetic Energy, Exploding Carts, & Volume

December 11, 2018 / Marta R. Stoeckel / 2 Comments

AP Physics 1: Kinetic Energy

I am being compensated by Pivot Interactives as part of their Chemistry Fellows program.

Students used Pivot Interactives to collect data for a relationship between an object’s starting height and its velocity at the bottom of a ramp to work toward a relationship for kinetic energy. Because the activity included directions for how to make each measurement, I got complacent and rushed through the pre-lab discussion, which meant some students were lost on the goal of the activity. I think I would have been better off taking a little more time, and pointing out connections between the directions in the activity and the measurements we discussed.

Physics: Exploding Carts

To start working toward momentum conservation, students launched pairs of carts off each other and plotted the ratio of the masses and the ratio of the velocities. Rather than measuring the velocity, we worked out that since the carts have a pretty constant velocity after the explosion, if they hit the end stops simultaneously, the ratio of the distances is the same as the ratio of the velocities. I like that this forces students to start making some predictions about how they need to adjust the distance, rather than waiting until the end to come up with a model.

Chemistry Essentials: Volume

The Modeling Instruction chemistry curriculum has a lab I really like to show that 1 cm³ = 1 mL, but I’ve struggled to make it work for my students. Both when I’ve used empty geometric solids and a selection of cylinders, doing the math to calculate the volume in cubic centimeters has been a huge hurdle. Today, I tried the lab using plastic cubes that are 1 cm on each side and it finally went smoothly. Students were actually paying attention to the relationship, rather then getting lost in the math to calculate the solid volume.

Day 63: Work, Quiz, & Histogram Interpretation

December 10, 2018 / Marta R. Stoeckel / 1 Comment

AP Physics 1: Work

To introduce work, I had students pull a cart up a ramp to a consistent height, but changing the angle. They then sketched force vs. distance graphs and saw the area was pretty consistent.

Physics: Quiz

We wrapped up Friday’s mistakes whiteboarding, then moved into a quiz on impulse. I’m finding students are loosing track of the different variables we have, which is making it tough to use the equations accurately. I think we might take some time soon to do a “glossary” of all the variables we’ve gotten so far this year to see if having a reference like that helps.

Chemistry Essentials: Histogram Interpretation

To wrap up Friday’s labs on mass and change, I projected some histograms of the class results. The discussion ended up being a lot of me asking a question, followed by one student responding, which is not what I like to go for. I need to spend some time thinking about better prompts I can use on these graphs to get more student-to-student discussion going.

Day 62: Quiz Day, Mistakes Whiteboarding, & Burning

December 7, 2018 / Marta R. Stoeckel / 2 Comments

AP Physics 1: Quiz Day

Students took their unbalanced forces quiz. I included an experimental design problem from the 2016 AP Physics 1 exam but told students I was essentially using it as a pre-test since I haven’t had them try any of that sort of problem yet and want to see how well they are translating what they’ve done in the lab to written problems.

Physics: Mistakes Whiteboarding

Students did some mistakes whiteboarding with yesterday’s problems. I was wary of how it would go in my 6th hour, since I only have eight students and they chose to work in one large group yesterday. There was a lot of great conversation yesterday, but it turns out a lot of students had written down steps without being clear on why they were taking that step, so this was a good opportunity for students to clarify those gaps.

Chemistry Essentials: Burning

Students carried out the experiments they’d planned yesterday to see how mass changes during dissolution. Afterward, they burned steel wool on a balance to get one more example. On Monday, we’ll discuss the results. I collected all of the changes in mass in a spreadsheet to produce class histograms of the results that we’ll also discuss on Monday.