Day 136: Board Meeting, Shadows, & Limiting Reactants

AP Physics 1: Unbalanced Torque Board Meeting

Students whiteboarded their results from yesterday. They quickly and easily made the connections I was after and the idea of rotational interia seemed to click well.

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Physics: Shadows

I did a quick intro to ray diagrams. I like to clap some chalk dust over the beam from a laser pointer to show the light travels in a straight line. This year, I followed up with clapping chalk dust over a flashlight beam to see the cone of light and motivate drawing multiple rays, which worked very nicely. Students then played with shadows and drew ray diagrams to explain their observations.

Chemistry Essentials: Limiting Reactants

Students worked on some limiting reactant problems. Based on some questions students asked yesterday, we also revisited a reaction we’ve done with magnesium and hydrochloric acid. I set up one flask with indicator and hydrochloric acid to use as a reference. In the other two flasks, I also added magnesium and tasked students with making observations to determine what the limiting reactant was in flasks 2 and 3, which they answered using a CER.

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Day 112: Coulomb’s Law, Spring Force Revisited, & Skew Dice

Today was our first day back from spring break and the first day of a new trimester.

AP Physics 1: Coulomb’s Law

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

We dove right in with a lab on Pivot Interactives to discover Coulomb’s Law. We’re going to be cutting it pretty close on squeezing everything in before the AP exam, so I was much more direct than usual about what needed to be done by the end of the hour and how long I expected tasks to take, and that seemed to help students meet the timeline I had in mind. I need to make that a habit for the next few weeks.

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Physics: Spring Force Revisited

We’re getting ready to start vibrating springs, so today we revisited Hooke’s Law. I asked students to make some predictions about how the slope of two different springs should compare before collecting any data, which was tricky since they haven’t thought about what the spring constant actually means for a while, but I think they got where I want them to be.

Chemistry Essentials: Skew Dice

A lot of my students either haven’t had chemistry since trimester 1 or came to me from the other Chemistry Essentials teacher, so I treated today like the first day of school and tried to set a tone for the term. I tasked students with writing a CER to answer whether skew dice are fair. In the past with this activity, I’ve had some trouble convincing students they need a lot of data, so I started by asking students to collect evidence that a regular dice is fair before we got out the skew dice, and students pretty easily recognized they needed a lot of rolls with the regular dice to get a distribution that makes sense.

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Day 86: Projectile Practical, Bouncy Ball CER, & Lauric Acid Phase Change

AP Physics 1: Projectile Practical

Students started working on predicting where a marble rolled off the edge of a table will hit the floor. As a wrinkle, I left it open how to set up a ramp to launch a marble and how to measure the horizontal velocity, then had students write a procedure. Groups exchanged procedures with the goal that they should get the same velocity as the group who wrote the original procedure. My goal is for students to get some low-stakes feedback on this kind of writing.

Physics: Bouncy Ball CER

Students finished up with the bouncy ball lab we’ve been working on and whiteboarded CER statements for what is dissipating the bouncy ball’s energy. There was good consensus that the impact has a much bigger effect than air resistance. We used a worksheet to scaffold the pre-work for this activity, so there wasn’t as much variety as when I leave it wide open, but I think students were more successful than they would have been without it.

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Chemistry Essentials: Lauric Acid Phase Change

Students collected data for phase changes of lauric acid. A few groups weren’t stirring, which made their data messier, but the patterns are pretty clear overall, even on the data table.

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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.

ap practical

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.

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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.

chem prac

Day 49: Newton’s 3rd Law, Whiteboarding, & Polyatomic Ions

AP Physics 1: Newton’s 3rd Law

Students predicted the relative forces on two carts in various collisions, then we tested them using a pair of carts with force sensors. I really like using hoop springs for this since it gives a very clear visual in addition to the force vs. time graphs.


Physics: Whiteboarding

Students whiteboarded the problems they worked on yesterday for a gallery walk. We set up the packet to re-use the problems we had that just deal with representations.

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After discussing the problems, I showed students a video I’d recorded on our elevator and asked them to write a CER for whether I took the elevator up or down.


Chemistry Essentials: Polyatomic Ions

We added polyatomic ions to the formula writing we’ve been doing. Students seem to be getting the hang of how to figure out the formula. Some students have figured out the “flop and drop” strategy, and others are opting to draw the simplified Lewis dot structures we’ve been using when they get stuck.

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Day 25: Friction, Groupwork Reflection, & Pressure

AP Physics 1: Friction

Students whiteboarded the friction lab from yesterday.  There was some good discussion and I can tell students are getting more comfortable talking about graphs. Its been a couple of years since I last did this lab, and the results are as messy as I remember, but students already seem to have a clearer idea of what the coefficient of friction is telling them, so I think it was worth the time.

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Physics: Groupwork Reflection

Today was a quiz day and the routine has become to spend the first part of the hour on an assessment doing some groupwork reflection. I spent some time on discussions about what skills students had used working on certain tasks to reinforce the value of multiple abilities. I have one class that seems to be buying in to valuing multiple abilities more than the other, but I think progress is happening on that front.

Chemistry Essentials: Pressure

To wrap up gas laws, I did a few demos. Before each one, I had students whiteboard a CER with their prediction. My favorite is a demo where I put a pipe between a large and a small balloon with each balloon clamped shut. Students have to predict what will happen when I remove the clamps. The version I first saw calls for putting a very small amount of air in the little balloon, so it isn’t stretching much, which forces air into the big balloon when you remove the clamps. I prefer inflating the small one enough that the rubber has stretched and, when the clamps are removed, the air just stays put in both.

pressure demo

Day 112: Rotation, Free-Fall, & Skew Dice

Today was the first day of a new trimester.

AP Physics: Rotation

Students used Pivot Interactives to make angular position vs. time graphs for several points on a disk with a constant angular velocity and a point on an accelerating disk. Back in September, my students who took calculus last year were able to make a lot of connections when we did graphs for linear motion. One of the great things about returning to circular motion now is my students currently taking calculus now have enough background knowledge that they were able to make some very similar connections today.


Physics: Free-Fall

To kick off projectile motion, students worked through a worksheet I got from Michael Lerner where they were asked to describe the motion of a falling orange using a variety of tools from earlier in the year. This seemed to help some student synthesize and connect a lot of ideas from earlier in the year.

Chemistry Essentials: Skew Dice

A lot of my students haven’t had chemistry since first trimester, so I wanted to reestablish some class norms. I used Frank Noschese’s subversive grouping to get students into group, then had them whiteboard a CER to answer whether skew dice are fair. Time got a little tight, so a lot of groups collected less data than I normally would push for, but in the follow-up discussion, that gave us the opportunity to talk about the value of getting as much data as possible.

Day 100: KVL Diagrams, TIPERs, & Formula Writing

Today classes were shortened due to a pep fest.

AP Physics: KVL Diagrams

We had a very brief discussion about the results of the labs from Wednesday and Thursday; students were consistently very successful at picking up on they key patterns I wanted them to see. I also introduced them to Trevor Register’s KVL diagrams. I like to pair that with color-coded current paths on the circuit diagram.


Physics: TIPERs

Students worked through some conceptual problems on impulse and momentum, mostly taken from TIPERs to get them thinking about what the equations we have so far really mean. A lot of groups really wanted to start by guessing an answer, then come up with some physics to justify it, rather than the other way around. I’ve been encouraging students to use CER with these types of problem, starting with the evidence and working towards the claim, but I’m tempted to try and talk my department into switching to ERC to make the evidence first more explicit.

Chemistry Essentials: Formula Writing

Playing the mistakes game yesterday seemed to help some students start to make sense of writing chemical formulas, though a lot of students still need more practice. Today, I gave students some formulas and asked them to determine whether they are possible based on what we know about bonding. This seemed to help the concepts click for a few more students.

Day 88: Board Meeting, Energy CERs, & Periodic Trends

AP Physics: Board Meeting

Students whiteboarded their results from the standing waves lab and the wave equation came nicely out of the discussion. I usually give students a minute or two to pre-discuss with their lab group once we circle up with the boards, but I think I can skip that time in my 2nd hour; they dove immediately into asking questions and making comments across groups, which is a great sign of how comfortable with each other and with talking physics.

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Physics: Energy CERs

Students wrote CERs with their lab groups to make qualitative predictions about objects like the seismic accelerator and a ballistic pendulum. A lot of groups struggled a lot with what good reasoning looks like, which is not surprising. We’ve backed away from reasoning tasks in Physics this year because many students are struggling on the quantitative problems, but I need to remind myself that students need the reasoning tasks to practice the sensemaking we want them to do on problems.

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Chemistry Essentials: Periodic Trends

Students used yesterday’s cards alongside their periodic tables to start looking at the patterns in the periodic table. Students made a lot of good observations and started asking questions about the legs used to represent valence electrons, which should make for a nice lead in to atomic structure.

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Day 77: CER, Mistakes Game, & Particle Diagrams

AP Physics: CER

Students have been struggling to explain their reasoning effectively, so we took a day to do some TIPERs problems on projectiles and energy using the CER framework. Most groups started with their claim, so I think next time, I will give some time for students to draw and interpret diagrams before I ask them for an answer. Its tempting to see what would happen with a goal-less TIPERs problem.


Physics: Mistakes Game

We played the mistakes game with yesterday’s pie chart problems. This is the first time I’ve done it this trimester, and I was surprised at how many students were very nervous about the prospect of presenting a board with unintentional mistakes, even after some discussion about whether anyone would know whether or a not a mistake was intentional. I need to keep working on building a sense of community and safety in this course.


Chemistry Essentials: Particle Diagrams

I showed students some examples of thermal expansion and had students whiteboard particle diagrams to explain what was happening. A few students made some great connections to the labs we’ve done.