Day 43: v-t Graphs, Board Meeting, & Chemical Change

November 8, 2017November 13, 2017 / Marta R. Stoeckel / Leave a comment

AP Physics: v-t Graphs

Students took their first stab at solving problems for objects with a constant acceleration using velocity vs. time graphs. Groups were consistently getting the problems down pretty quickly, so we did a gallery walk of solutions for these problems rather than a full whiteboarding session. My students with some calculus knowledge are getting genuinely excited about the connections between physics and calc, which is a lot of fun. I also had some students think week talking about how momentum vs. time graphs fit with what we’re doing now, which has me really excited to start the Newton’s 2nd Law lab next week.

graph soln.jpg

Physics: Board Meeting

Students whiteboarded the results of the force of gravity lab. The results were pretty good and I had some students speaking up who are usually quiet during whole-class discussions. I’m also seeing students get more confident finding the line of best fit and translating y=mx+b into “physics”.

fg lab.jpg

Chemistry Essentials: Chemical Change

Students did a lab observing several chemical reactions to recognize signs of chemical change. One of the reactions produced a precipitate, and it was interesting that a lot of students were not convinced the precipitate was a solid since it was a fairly fine powder.

chem change.jpg

Day 41: Board Meeting, Mistakes Game, & Periodic Table

November 6, 2017November 13, 2017 / Marta R. Stoeckel / Leave a comment

AP Physics: Board Meeting

We had the board meeting for last week’s ramp lab. Students were pretty successful at picking out the key concepts, though the results were a little messier than usual, which made it tough to compare results for different angles and cart masses. Next year, it may be worth having each group do two angles or two masses. I’ll also take more time to introduce students to the photogates. The students in calculus had some great reactions when they realized the slope of the position vs. time² was half the slope of the velocity vs. time graph.

Physics: Mistakes Game

Students played the whiteboard mistakes game with Friday’s free-body diagram problems. Lots of groups had great conversations about the forces on an object already moving and the language of interactions, including many of the ideas from the interaction stations, really helped them convince each other whether or not there should be a force. I also took a few minutes prior to presenting any whiteboards to talk about what it looks like to get something out of this when you’re not presenting, and saw a lot more students than usual with their own work out.

Board with intentional mistake for a ball at the peak of a throw

Chemistry Essentials: Periodic Table

We revisited Friday’s card sort. When I looked over students’ work from Friday, it looked like many of them got stuck on the word “pattern” in the directions because they were looking for something that was all the same, rather than a trend. Today, I had them get out actual periodic tables to use as a guide to set out the cards. From there, it was much easier to scaffold students to identifying interesting trends. Students were also really interested in things like how we discover new elements, or how they get named.

Day 39: Ramp Whiteboards, FBDs, & Electrolysis

November 2, 2017November 13, 2017 / Marta R. Stoeckel / Leave a comment

AP Physics: Ramp Whiteboards

Since a recent quiz used a free-response problem from the AP Physics exam, I gave students part of the hour to use the scoring guide to review their work. Students seemed to like seeing the level of detail the College Board is after.

Afterward, students prepared whiteboards for the ramp lab we’ve been working on. I made some changes to my approach and can tell I need to do a little more work on helping students interpret the graphs and data tables from the photogates. Overall, results are looking pretty good.

Physics: Free-Body Diagrams

We discussed some of the interaction stations to get to the point of defining a few key types of forces. Afterward, I introduced them to interaction diagrams and free-body diagrams using the hover puck in an activity adapted from Kelly O’Shea. For the puck traveling at a constant velocity, one of my hours had some really good small group discussion about whether there is a forward force on the puck, though neither class got to a whole group discussion today.

Chemistry Essentials: Electrolysis

We did a gallery walk to go over yesterday’s problems. I also showed students an electrolysis apparatus to have some conversation about how we know water is two hydrogens and an oxygen.

Day 34: Board Meeting, CAPM Practical, & Freezing Acid

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

AP Physics: Board Meeting

We had a board meeting to wrap up the buggy lab. A lot of students who are normally quiet in whole class discussions spoke up today, which was great. In addition, there were some interesting observations that don’t always come up, like the student who commented the intercept did not depend on the slope. At the end of the hour, I also asked groups to whiteboard a CER for what the momentum vs. time graph should look like and, while we didn’t have a chance to discuss the boards, groups consistently were on the right track and not only connected the buggy lab to the definition of momentum, but to Newton’s 1st Law by discussing whether they could identify unbalanced forces on the buggy.

Physics: CAPM Practical

Students started working on a constant acceleration lab practical where they try to get a marble rolling down a ramp to land in a cup attached to a moving buggy. Some groups got a starting position for the marble while others got a starting position for the buggy. A lot of groups had trouble focusing on individual pieces of the task; tomorrow, I may take a few minutes to talk through the major steps students need to take. I’m also seeing students continue to struggle with confidence; they are nailing the problems, but just don’t believe that they get it, which makes it difficult to approach a challenging lab practical.

Chemistry Essentials: Freezing Acid

We discussed the results of yesterday’s lab. At the end of the hour yesterday, a lot of students didn’t seem convinced that temperature stays constant during a phase change, partly because they were focusing on their data tables and saw very small temperature variations. Today, I projected a graph from one of the groups for the discussion, and students saw much more clearly that the temperature is pretty constant. When students graph in Desmos, I usually allow one group member to make a graph as long as everyone sketches it (I don’t have a good way for students to print), but I think that’s making it too easy for most of the group to just glance at the graph so I need to work on ways to get students looking closer. I usually have a handout for labs in this course, so I’ll probably add some questions to prompt students to look carefully at their group’s graph to the next lab to see if that helps.

Day 29: Conservation of Momentum, Annotating Graphs, & Temperature vs. Heat

October 16, 2017 / Marta R. Stoeckel / Leave a comment

AP Physics: Conservation of Momentum

We had a board meeting on last week’s conservation of momentum lab. As part of their whiteboards, I asked students to write a CER on whether their results made sense and encouraged them to use Newton’s Laws in their thinking. The 1st Law was a much more popular approach than the 3rd Law, but I was pleased at the connections were making.

ap cons.jpg

Physics: Annotating Graphs

Students started working on some problems to annotate velocity vs. time graphs and write equations for the area. I think this is helping some of my students to make more connections to what the graph actually represents, which will be an important stepping stone to solving problems. I also added some problems that just ask students to sketch and annotate a v-t graph from the kind of written description that would start a problem.

phys anno

Chemistry Essentials: Temperature vs. Heat

We took some notes on heat and temperature, then I asked students to predict whether there would be a larger temperature change when I added a small amount of boiling water or a large amount of warm water to a large beaker of room temperature water. Students seemed to wrap their heads around the difference and were able to explain why the warm water produced a bigger temperature change after the demo.

chem temp.jpg

Day 26: CoM Board Meeting, Breaking Down Problems, & Gas Laws

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

AP Physics: Center of Mass Board Meeting

We had a board meeting to discuss the results of the video analysis from the last few days. I asked students to write a CER for whether the forces on each system of pucks were balanced or unbalanced. This lead nicely into some conversation about what exactly we mean by the two -puck system. I ended up wishing students had more experience interpreting position vs. time graphs prior to this discussion; we’ve mostly worked with velocity vs. time graphs so far, and the various uncertainties piled up to make it look like the velocity was changing. The position vs. time graphs were much more convincing, but students weren’t as likely to look at those.

Afterwards, we played with the coupled carts from Kaar, Pollack, Lerner, and Engles’ The Physics Teacher article. The graphs were very satisfying.

Top: v vs. t for each cart, Bottom: p vs. t for system

Physics: Breaking Down Problems

On the last quiz, a lot of students really struggled to interpret the problems, so we spent some time today on how to break down a physics problem. As we discussed how to approach a problem, we took time for students to apply each step to the problems on the most recent quiz.

Chemistry Essentials: Gas Laws

We used the results of yesterday’s simulation to develop the gas laws. I’ve found a lot of my students really struggle with algebra, so, rather than developing equations, we came up with statements using proportional reasoning which students then applied to some problems. Some of my students who really struggled to manipulate the density equation were very successful with today’s gas laws problems, so I think this approach was a success.

Day 25: Center of Mass, Board Meeting, & Gas Laws

October 10, 2017October 11, 2017 / Marta R. Stoeckel / Leave a comment

AP Physics: Center of Mass

Students continued yesterday’s video analysis, based on the article by Taylor Kaar, Linda Pollack, Michael Lerner, and Robert Engles in The Physics Teacher. Today, students analyzed the motion of four hover disks linked into a square from several different perspectives. They were a little bothered that it was tricky to spot the center of the square, but I like that we’ll be able to have a conversation about whether there has to be any mass at the center of mass.

Physics: Board Meeting

Students whiteboarded their results from the video analysis the last few days. Framing this around a CER with a more specific question than usual had the desired effect and I saw students keeping much more complete records than usual. Students are continuing to struggle with recognizing the physical meaning of features on the graph, so I need to keep giving students opportunities to work on that.

Chemistry Essentials: Gas Laws Simulation

Students used the PhET Gas Properties simulation to take quantitative data for the ideal gas laws. I think the class would have benefited from a little more discussion prior to using the simulation to set up what we were measuring and why, rather than just giving them an assignment in Google Classroom that told them what to measure. However, students were very successful in recognizing the quantitative relationships I wanted them to see.

Day 23: Elevators, Board Meeting, & Pressure

October 5, 2017October 11, 2017 / Marta R. Stoeckel / Leave a comment

AP Physics: Elevators

I took some time today to introduce students to the CER framework. I showed them a force vs. time graph I made by riding the elevator with a mass hanging on a force sensor, then asked them to determine whether I was riding the elevator up or down. We haven’t done much with unbalanced forces yet, but they were pretty successful determining which direction I rode it.

Physics: Board Meeting

Students whiteboarded sketches of their graphs from yesterday. Its been taking longer and longer for groups to prepare whiteboards, so I think I will try setting a time on the SMARTBoard to try and speed things up. I also found a lot of groups were missing information we’d discussed recording prior to the lab yesterday, so I think we need to revisit lab notebook practices. The discussion was very abbreviated, so we only got a chance to discuss a little about the position vs. time graphs, but students were able to recognize the key ideas. On Monday, we’ll talk about the v-t graphs and look at some variations.

Chemistry Essentials: Pressure

To introduce pressure, students watched a balloon in a vacuum chamber, then whiteboarded what they thought was happening. Students were pretty successful at coming up with useful ideas to explain what they saw and inventing the idea of pressure.

Afterward, we boiled water in the vacuum chamber. We ran out of time to whiteboard it, but, on a whim, I got out my thermal camera and recorded a video to show the water stays cool.

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.

Chemistry Essentials: Density

Students found a relationship between mass and volume for water, which I used to introduce density. This was one of the times I really liked particle diagrams, since it made density much more concrete than an equation would. A lot of groups skipped finding the slope of their line, so I need to keep reinforcing that the slope is important.

Day 12: Springs, Buggies, & Board Meeting

September 20, 2017October 11, 2017 / Marta R. Stoeckel / 1 Comment

AP Physics: Springs

Students pulled on springs with force sensors to get data for Hooke’s Law. I usually have students who expect a horizontal spring to behave differently than a vertical one, so I took advantage of the force sensors to have students collect data for one of their springs in both orientations. When groups started to notice they have the same slope in both orientations, many of them started talking about whether that makes sense, which was fantastic.

Physics: Buggies

Students finished their data collection and prepped whiteboards for the buggy lab. One student came up to tell me he was thinking about how he could use the data from this lab. In particular, he wants to give the slow buggy a head start, then figure out where the fast buggy will pass it. I let him know that will be our next lab practical.

I’ve got a decent number of students who are struggling with math skills, such as finding slope or plotting negative values, and I need to adjust how I’m addressing that. I’ve been giving small group instruction as needed, but I’m spending a lot of time with just a few groups and missed others who were on the wrong track with this lab until pretty late. I’m toying with some options like providing math “cheat sheets” or having some mini lessons during the class for groups who need help, but I’d really like to develop a culture where students are relying on each other for some of that.

Chemistry Essentials: Board Meeting

Today went pretty smoothly; I think yesterday’s work on norms helped, though I need to make sure it doesn’t feel like a punishment next time. When I reviewed the norms at the start of class, a student asked if I actually like about teaching them, so I spent a few minutes sharing some examples of when I’ve really enjoyed their energy.

Students whiteboarded their results from this week’s volume lab. There are a big range of math skills in the class, but once groups compared the values on their data tables, they had an easier time getting at what the slope means. We hadn’t talked about the thickness of the sides, so I was excited when a student asked how it would change the results if the shapes were made of much thinner plastic.