Day 118: Board Meeting, Projectile Problems, & Balancing

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

AP Physics: Board Meeting

We had our board meeting for yesterday’s lab on centripetal force. I approached it as three mini board meetings since students had done experiments for how three different variables affect the force. The units on slope ended up being a very powerful way for students to see the connections between their three graphs. It was especially exciting when we got to the force vs. mass graph and students saw the connections to Newton’s 2nd Law. One class noticed the slope on the force vs. 1/radius graph has units of Joules, but I’m not sure of the significance of that yet.

Physics: Projectiles

Students whiteboarded yesterday’s problems for a gallery walk. They are consistently viewing free-fall as just a special case of models we’ve already covered, which made the problems pretty easy. Afterward, students started working problems for horizontal projectiles.

Chemistry Essentials: Balancing Reactions

After some discussion about the labs from the past few days, students worked on some problems balancing chemical equations. The students who started by sketching a particle diagram were generally very successful at seeing how to balance. A few students got tripped up determining when individual letters in a formula represent individual atoms, especially when the formula included a polyatomic ion, but were getting the hang of it after a couple problems.

Day 117: Central Net Force, Free Fall, & Balancing Equations

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

AP Physics: Central Net Force

Students worked on an activity in Pivot Interactives to find how speed, mass, and radius affect the centripetal force. One of the great things about this time of year is my students not only have a lot of skills, they are very confident in those skills, so I got to listen to good conversations about experimental design, uncertainty, and linearization without stepping in to do any coaching.

Physics: Free Fall

Students worked on some free-fall problems. There was a pretty even split between groups who relied on velocity vs. time graphs and groups who relied on energy. For the first time, I had a couple of groups draw separate v-t graphs for when the object was rising and when it was falling, which helped them organize their thinking.

Chemistry Essentials: Balancing Equations

Students used the PhET Balancing Chemical Equations sim to start exploring what it means for a chemical equation to be balanced. This not only seemed to help students make sense of balancing, but to do some retroactive meaning-making on the work we’ve been doing on representing reactions.

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

February 5, 2018 / Marta R. Stoeckel / 1 Comment

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 89: Superposition, Energy Practical, & Atomic Models

January 31, 2018January 31, 2018 / Marta R. Stoeckel / 1 Comment

AP Physics: Superposition

After a little playing with the snakey springs, students went to Pivot Interactives to explore wave superposition. There was a lot of great discussion about whether the wave pulses passed through each other or bounced off each other with students making some pretty detailed observations of the pulses.

Physics: Energy Practical

Students worked on using conservation of energy to determine where to place a photogate on a ramp to get a cart moving at a certain velocity. A lot of groups had trouble interpreting their height measurements; I think a lot of them were not keeping track of where they placed the reference height. One group recognized this is pretty similar to the kinetic energy lab we did and used their lab results to confirm today’s calculation.

Chemistry Essentials: Atomic Models

I still haven’t found a way I’m really happy with to address the state standard about the evolution of atomic models, but today was the day I tried. I used a POGIL activity where students read some summaries of the major steps in the atomic model and answered some questions. A few students felt overwhelmed by the length of the reading, so we talked about how to use the section headings to make it more manageable. I liked this better than last tri’s jigsaw since doing the full reading seemed to help more of them see the different models as part of the same story.

Day 87: Standing Waves, Whiteboards, & Elements Card Sort

January 29, 2018 / Marta R. Stoeckel / Leave a comment

AP Physics: Standing Waves

Between parent teacher conferences and a bad cold, I failed to actually assign the Pivot Interactives activity I’d planned for Friday to any classes, which made it a little tricky for them to complete. Today, I actually assigned it and they collected data to find a relationship between the wavelength and frequency of a standing wave. The upside is my students had a very self-directed activity while I was still not at 100%.

Physics: Whiteboarding

The majority of my students attempted the problems I left for them to do with Friday’s sub, which is a nice sign of progress. Today, we spent some time whiteboarding the problems, mostly using gallery walks. I gave each problem to at least two different groups so they could compare answers and approaches before the gallery walk, which helped build some confidence. In another sign of progress, in one group that is usually pretty quick to ask for help, one member insisted that today, they would discuss every question before they asked me and told me to wait several times when her groupmates called me over. In the end, they were able to reason their way through every question they had.

Chemistry Essentials: Elements Card Sort

Students worked on a card sort activity loosely based on Mendeleev’s process for developing the periodic table. Each group picked two properties to sort by (one for columns and one for rows), and quickly noticed that other patterns started popping out. I also got a lot of students eager to know what some of the features of the cards represent, so it will be nice to tie some upcoming activities back to this one. Though, I need to brush up on my history a little bit to explain how Mendeleev knew some of these properties.

Day 84: SHM Trio, Kinetic Energy, & Lauric Acid Take 2

January 24, 2018 / Marta R. Stoeckel / 2 Comments

Yesterday was a snow day.

AP Physics: SHM Trio

Students analyzed a video from Pivot Interactives of a pendulum, a spring, and a rotating disk in synchronized simple harmonic motion. I overheard some really good conversations about differences between the x-position vs. time and y-position vs. time graphs for the pendulum; a few students relate it back to the projectile Pivot Interactive we’d done and tried to imagine a camera that just showed the vertical motion of the pendulum.

Physics: Kinetic Energy

Students started collecting data to find a relationship between the change in height of a cart on a ramp and the velocity at the bottom. On the elastic potential energy lab, a lot of students just measured the height of the cart, rather than the change in height, so I spent some extra time on the pre-lab discussion to make sure students saw why the change is important.

Chemistry Essentials: Lauric Acid Take 2

We took another shot at finding the freezing point of lauric acid since the weather on Monday cut us short. A few students who’d collected some data were frustrated that they had to start fresh, rather than picking up where they left off. It will probably be worth spending some time tomorrow on why they had to start fresh, especially since it connects to what the graph physically means.

Day 71: Board Meeting, Practical, & Density Again

January 4, 2018January 4, 2018 / Marta R. Stoeckel / Leave a comment

AP Physics: Board Meeting

Students whiteboarded their graphs from yesterday’s video. Once I had my 2nd hour find a class average for the slopes of their vertical velocity vs. time graphs, everything fell beautifully into place and there were even gasps when one student sketched a free-body diagram. In my other hour, a lot of groups skipped the directions for making the v-t graph and tried to take shortcuts that didn’t work, so I had to step in a little more. This reinforces my thoughts yesterday that I should have spent some time discussing the midpoint method.

pm graphs.jpg

Physics: Unbalanced Forces Practical

Students started a practical to predict the time it will take a cart to roll down a ramp given the cart’s mass and the ramp angle. For the first time, I had several students ask if I could just do a diagram or calculation for them, so I left the pen I usually carry at my desk and kept my hands in my pockets to avoid encouraging that.

ramp prac.jpg

Chemistry Essentials: Density Misconceptions

Today, I have students blocks of the same material, but different volume, and asked them to determine whether volume affects density. A lot of groups had trouble funding the volume with a ruler, rather than later displacement, so I should have spent a little more time on a pre-lab discussion connecting yesterday’s volume measurements to today’s.

density (1).jpg

Day 70: Projectiles, Forces Reintroduction, & Density

January 2, 2018 / Marta R. Stoeckel / 1 Comment

AP Physics: Projectiles

Students did an activity on Pivot Interactives to watch the motion of a projectile from three different vantage points and produce position vs. time and velocity vs. time graphs. From what I saw, most groups got pretty good results. This was the first time students saw the midpoint method for finding slope of a curve, and I think I should have spent a little more time introducing that. We can have some discussion about it tomorrow.

Physics: Forces Reintroduction

Especially because a lot of students really struggled with the forces assessment right before break, we started this week getting back into the swing with some problems similar to what we worked on right before break. Before break, I was also seeing more and more students getting off-task during time with their groups, so I spent some time sharing my observations and having some discussion about how that fits with what it takes to be successful in a class like this.

Chemistry Essentials: Does shape affect density?

I had students determine whether the shape of a block affects its density using a set of aluminum blocks with different shapes, but the same volume. Last tri, I’d asked students to predict the shape of the mass vs. volume graph, but it was tricky to collect class data and the graph was kind of boring since I didn’t have much variety of volumes. This approach got the same misconceptions out on the table, but gave more meaningful results.

Day 60: Kinetic Energy, 3rd Law, & Melting Mass

December 7, 2017 / Marta R. Stoeckel / Leave a comment

AP Physics: Kinetic Energy

To introduce kinetic energy, I had students work through a Pivot Interactives activity to find a relationship between the starting height of a puck and its velocity at the bottom of a ramp. I ran out of time to have a pre-lab discussion yesterday, so tried to have one in the computer lab today. I had more students then usual struggling with what to measure or what to graph, and I think that was because a lot of them started the activity rather than fully engaging in the discussion. Once they got rolling however, students warmed up to the interface pretty quickly.

Physics: 3rd Law

We collided carts with force sensors to check the predictions students made yesterday. I spent more time than usual talking about why I asked them to make predictions I know are likely to be wrong since confidence has been such an issue for students this year.

Chem Essentials: Melting Mass

Students continued the Modeling Instruction mass and change labs. Today, they melted ice and mixed sodium carbonate with calcium nitrate; a lot of students really liked that reaction and were observing close enough to notice the precipitate causing the cloudiness. I added a mini-exploration of the zero button on the balance, which I was pretty happy with. A lot of the students in the course struggle with mathematical reasoning, and taking a few minutes to play with the zero button and the readings on the balance seemed to help make its purpose more concrete.

Day 127: Oscillating Particle Model & Problem Scoping

April 4, 2017July 14, 2017 / Marta R. Stoeckel / Leave a comment

AP Physics: Oscillating Particle Model

Students whiteboarded their video analysis results for the trio of objects in simple harmonic motion. I haven’t done a lot of circular motion in the past, so when we discussed the spinning disk, I was intrigued by how many students were convinced the angle in the video was responsible for the changing velocity. On a whim, I had students sketch the disk from directly above, then had them sketch velocity vectors, including components, at a few points around the disk, which nicely convinced students that they would see similar graphs for the horizontal motion no matter what the viewing angle.

shm trio

Earth Science: Problem Scoping

This unit includes an engineering project to plan removing a dam from a river. I gave students a memo from their imaginary client and had them do some problem scoping. One of the questions I ask is what background knowledge they will need, which can nicely set up a unit, but students did not identify anything about rivers or erosion as useful knowledge on this project. The memo mentions sediment transport as a major challenge in removing the dam, but I don’t think students saw that as something that would require background knowledge to understand. Even when I handed out the unit’s learning targets, students did not name the target about describing river behavior as one that will be useful. I need to think about how I will address that during the unit.