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 58: Scoring Guide, Broken Circles, & Steel Wool

December 5, 2017 / Marta R. Stoeckel / 1 Comment

AP Physics: Scoring Guide

The tri 1 final exam included some free response problems off past AP tests, so today I gave students the scoring guides and some student samples to make sense of the scoring before letting them see their own tests. One of the problems was problem 3 off the 2016 free response and, inspired by a participant in Greg Jacob’s AP Summer Institute, I used rubber bands to make a bumpy ramp so we could actually try out the experiment in the problem. The class had some good discussion about key takeaways, like the importance of explaining EVERYTHING. Students also noticed that the student samples with high scores had a lot of marking the text.

Physics: Broken Circles

I struggled to get the class culture I wanted in my physics class last trimester and, with students shuffling between hours and about half coming from the other physics teacher, the new tri is a great opportunity to try again. Students worked on a broken circles activity from Designing Groupwork by Lotan & Cohen, then we had some discussion about what it took to succeed and how that fits with what effective groups in physics look like.

Chemistry Essentials: Steel Wool

This course is two trimesters long, and we only offer the second half during tri 3, so I’m restarting the first half of the course with a new group of students. Students measured the mass of steel wool before and after pulling it apart. To help students focus on good lab practice, I had them do the experiment once with minimal instructions. Then, we had a brief discussion to get at some sources of error before students completed the lab again with a handout and a paper plate to help catch stray bits of steel wool. Just like tri 1, I made a class histogram with Post-Its, but the results were much nicer this time.

Day 21: Lab Practical, More Problems, & States of Matter

October 3, 2017October 11, 2017 / Marta R. Stoeckel / Leave a comment

AP Physics: Lab Practical

Students worked on a balanced forces lab practical to determine an unknown mass given the tensions supporting it. I just made one set-up, and it was interesting to see that in one class, each group wanted to take their own measurements, while the other class wanted to just have one person take the measurements and record them on the whiteboard. The hour that took measurements as a whole class actually took longer to get everyone the data, but had a lot more conversation about what they needed.

Physics: More Problems

I’ve got enough students struggling with constant velocity that we took a day to do a Modeling worksheet that I usually skip. Talking to students, there were several groups who thought the area of the velocity vs. time graph only gave displacement in special cases. I’m also seeing a lot of evidence that students are losing track of the physical meaning of the graphs and their connections with the math. For example, when writing an expression based on a graph, a lot of students are using units and variables from the dowel lab, which tells me they know a procedure to turn y=mx+b into “physics”, but don’t have a conceptual understanding of what they are doing. These challenges have been a recurring theme in physics this year; we’re starting constant acceleration tomorrow, and I think I want to revamp the lab a bit to try and prevent some of these issues.

Chemistry Essentials: States of Matter

Students melted ice into steam and made observations and drew particle diagrams along the way. This led nicely into the idea that as the temperature increases, the particles are moving more. Students also made some nice connections to yesterdays’ demo with food coloring in water.

Day 19: Plickers, Dueling Buggies, & Quiz

September 29, 2017October 11, 2017 / Marta R. Stoeckel / Leave a comment

AP Physics: Plickers

After a quiz, I introduced students to Plickers. One piece of feedback I got from students last year was that they would have liked to practice multiple choice earlier in the year so, this year, I’m planning to spend part of each Friday on that. I have students read the question silently and vote on an answer, then vote again after talking to their peers. My 4th hour had some great, spirited discussion and was actually disappointed when I told them it was time to put the cards away and head to lunch.

Physics: Dueling Buggies

We wrapped up the dueling buggies lab practical. For the rear end collision, most of my groups got a crash position behind where both of the buggies started, so I paused the class to look at what results would make sense. I’m debating whether its worth having that conversation sooner next year, or if it is better to wait until there is a need. This fits with a pattern I’ve noticed this year where more students than usual are struggling to connect their graphs and math to what is physically happening.

I couldn’t get a volunteer to release the second buggy or to film the collisions for me, so here’s a video from a couple years ago.

Chemistry Essentials: Quiz

Students spent most of the hour on their density quiz. While I haven’t graded them yet, there were some stark differences in how students did on the quiz. Several students immediately made a connection to some of the worksheets and labs we’d done and found the quiz extremely easy. Others thought the quiz was completely unfamiliar and really struggled. I need to keep working on helping students to make connections across different days, as well as supporting my students in developing as independent thinkers.

Day 18: Trig It Out, Dueling Buggies, & Density Problems

September 28, 2017October 11, 2017 / Marta R. Stoeckel / Leave a comment

AP Physics: Force Problems

Students worked on using vector addition diagrams to solve balanced force problems (one of many things I learned from Kelly O’Shea). I really like that while many of my students still ended up using a version of components, they see where the components come from. Once students set up their vector addition diagrams, the slogan for the day was “Trig it out!”, a line from last year’s students.

Physics: Dueling Buggies

Students worked on the Modeling Instruction lab practical to predict where two buggies will collide. I didn’t give quite enough instruction to my 1st hour, but once I suggested they try drawing some representations and play with them, they started making some progress.

One of my goals this year is to help students value ways of being successful in class besides knowing the answer quickly, so as part of the lab practical I gave them a list of skills based on similar lists from Kelly O’Shea and Ilana Horn, then asked them to identify at least one example for each group member where they demonstrated one of those skills. I’m looking forward to reading their responses.

Chemistry Essentials: Density Problems

Students worked on some density calculations. Some students really struggled with the algebra, so I’m trying to decide whether that really needs to be in the course. Most are getting to a point where they are successful with the graph, and I think that is more valuable in the long term than using the equation.

I also handed back the first quiz; most students performed about how I expected, but I was surprised at how many students had underestimated how they did and were genuinely excited about their score. Several confirmed with me (multiple times, in one case) that they got to keep their quiz so they could show their parents. I need to work on reinforcing the connections between our day-to-day work and the assessments so that more students will see that kind of success.

Day 17: Vector Addition, Motion Detectors, & Water Displacement

September 27, 2017October 11, 2017 / Marta R. Stoeckel / 1 Comment

AP Physics: Vector Addition Diagrams

Students worked through an activity from Casey Rutherford to introduce vector addition diagrams. A few groups started thinking about how they could use trig and other math to do calculations with the shapes they made; one group even came up with the idea of components, which was awesome!

Physics: Motion Detectors

For the first half of class, we did the mistakes game for yesterday’s problems. Based on the mistakes several groups decided to make and the discussion that followed, I realized that a lot of students are drawing their velocity vs. time graphs to look like the motion maps.

After finishing the problems, we got out the motion detector and focused on what the time axis means. Watching the graph form live seemed to help some of the students who’ve been sketching graphs that look like motion maps.

Chemistry Essentials: Water Displacement

Students used displacement of water to find the volume and density of aluminum and brass blocks. I collected results to put on a class graph, and it was interesting to ask students to predict the shape of the graph. A lot of students expect the graph to have no pattern since the blocks are all different shapes. I may need to have them do some particle diagrams tomorrow to help compare.

Day 16: Systems, v-t Graphs, & Good Questions

September 26, 2017October 11, 2017 / Marta R. Stoeckel / Leave a comment

AP Physics: Systems

Students did the mistakes game (pretty much my default mode of whiteboarding if you can’t tell yet) for a free-body diagram worksheet. Both classes had some great discussion about whether there should be an upward force for a projectile while it is in the air and it helped a lot to frame forces as interactions. I ended up wishing I’d taken some time to revisit Newton’s 1st Law from the momentum unit since some students were having trouble with the idea that forces are balanced on an object rising with a constant velocity. I’ll probably spend some time reinforcing that tomorrow.

I also took this opportunity to introduce students to the idea of defining their system. Both sections had debates about different problems where they were trying to decide what was causing an upward force. That lead nicely into discussing how we could define our system to make each possible answer correct.

Physics: v-t Graphs

Students worked on sketching velocity vs. time graphs based on motion maps and position vs. time graphs. The calculus class started v-t graphs at the end of last week, so I had some students who not only finished quickly, but were eager to exercise their new knowledge by helping their peers, which was great. I had a lot of students who struggled with the idea that the horizontal axis on the graph represents moving forward in time; I want to try getting out the motion detectors tomorrow so they can watch the graph form in real-time to see if that helps.

Chemistry Essentials: Good Questions

We spent some time working on asking good questions. I prepped a whiteboard with an intentional mistake, and asked students about what they saw. Some were able to use the question stems to immediately get to a good question. When a student had an observation or an idea of where to steer me next, I had them share it and we formed a question as a class. Then, we went back to the remaining student whiteboards and were much more successful and focused than yesterday.

Day 15: Rubber Bands & Mistakes Game

September 25, 2017October 11, 2017 / Marta R. Stoeckel / Leave a comment

AP Physics: Rubber Bands

Both sections worked on drawing interaction diagrams and free-body diagrams, but one of my sections is about 30 minutes ahead and was able to get the problems mostly done last week. That section had asked about what the graph looks like when a spring is overstretched and Hooke’s Law breaks down, so we got out some rubber bands to try. I told students I hadn’t had a chance to collect my own data, so we’d be finding out together, and they seemed on board with that.

Physics: CVPM Mistakes Game

Students played Kelly O’Shea’s mistakes game with Friday’s worksheet on translating between different representations of constant velocity. I really like this worksheet for introducing the mistakes game since its easy to direct students towards meaningful mistakes. I usually talk about some stems for good questions, but this time, I also projected them, which seemed to help. When the discussion lagged, I used Post-It notes to feed questions to students, but another student would usually ask the question I had in mind before I could finish writing, which is a good reminder to give them time.

Chemistry Essentials: Density Mistakes Game

This class played the mistakes game with Friday’s density problems. I also used the question stems with them, but they struggled a lot more with asking good questions. I think they need a little more scaffolding; I might put together a whiteboard and have students prep questions in their groups. A lot of students fell back into some of the behaviors I’ve been trying to push back against with the work on norms, and I think some of that was a result of some students feeling confused and frustrated with the discussion.

Day 14: Friction, Multiple Representations, & Density

September 22, 2017October 11, 2017 / Marta R. Stoeckel / Leave a comment

Today is homecoming, so classes are shot and students are excited.

AP Physics: Friction

I decided not to take the time for a lab on friction, so I collected some data with a force sensor and motion detector and asked students for observations. I used the motion detector to help connect what the force was doing to what we know about momentum so far. Students pretty readily recognized the force of friction changed when the block when from being at rest to being in motion.

Afterwards, students took their second quiz. Last year, I had very few students complete retakes, so this year I’m giving them at least two in-class attempts at each learning target to try and normalize reassessment. So far, I’m hearing a lot of talk from students that suggests they are much more comfortable with reassessing than last year’s students.

Physics: Multiple Representations

Students worked on a Modeling worksheet to practice translating between position vs. time graphs, motion maps, and descriptions of motion. Overall, students did well and I think this helped reinforce the value of what came out of yesterday’s discussion. In the class where I see the most struggles with math skills, several groups chose to shuffle themselves today, and ended up needing much less support from me than usual. For the first time, however, I had some students who made graphs showing multiple positions for a single point in time. I need to probe their thinking a little more and think about how to address that when we go over the problems on Monday.

Chemistry Essentials: Density

Students worked on a Modeling worksheet connecting particle diagrams and density. I got a little nervous when a very large group gathered around the para who assists the class, but they had some good discussions. I do need to think about how that will impact whiteboarding on Monday when 1/3 of the class worked as part of the same group.

Day 13: Board Meeting, Motion Maps, & Density

September 21, 2017October 11, 2017 / Marta R. Stoeckel / Leave a comment

AP Physics: Board Meeting

We whiteboarded the spring lab from yesterday. In both my sections, students had great observations and did a nice job of starting to talk about what the graphs mean with out too much prodding. There was a lot of great discussion about the limits of this model, as we tried to figure out whether the intercept on these graphs should be zero. One student also raised the point that if you overstretch a spring, it bounces back, so we was wondering if the linear relationship would still work. I might have them try it with rubber bands.

Physics: Motion Maps

We whiteboarded the buggy lab. I had a lot of trouble keeping students engaged in the large group discussion, I think partly because students didn’t use the ideas we developed in board meetings during the first unit, setting the tone that board meetings aren’t important. One thing that helped a lot was a student who was extremely willing to ask questions about what groups had done when their graphs were different from her group’s, which pulled a lot of students back into the discussion.

After the board meeting, I got out my Fridge Rover, a magnetic wind-up toy that maintains a pretty constant velocity, to introduce motion maps. I made marks on the board showing the rover’s position at regular time intervals, which drives home the connections between motion maps and the buggy lab students just did.