# Day 127: Oscillating Particle Model & Problem Scoping

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.

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.

# Day 126: SHM Trio & Water

AP Physics: SHM Trio

Students downloaded a Direct Measurement Video of three objects in simple harmonic motion and did some video analysis. There was lots of great discussion about why the pendulum’s y-position vs. time graph showed a different period than the x-position vs. time graph. I also really liked the conversations students had about whether the net force on each object is constant. My favorite moment was when a student called me over for help, and the person sitting next to her said “You need to think about it first!” The second student then started asking questions to help the first student figure out the answer she needed. Yay, students!

Earth Science: Where is Earth’s Water?

Students filled beakers with their prediction for how Earth’s water is distributed, then got the actual distribution and compared. I liked how doing their own prediction first made it much more dramatic when they got the actual results, and saw just how little of Earth’s water is in a form we can really use.

# Day 105: Dissipated Energy & Building

AP Physics: Dissipated Energy

Students analyzed video of their bouncy balls and collected evidence to argue whether the energy is primarily dissipated by air resistance or by the impact with the table. There was a nice variety of approaches and I was pleased by how many students went back to the fact that we neglected air resistance during projectile motion to make a prediction about whether it should matter here.

Physical Science: Building

Students worked on building their cargo carriers based on yesterday’s designs. To help keep the focus on the science behind their designs, I stopped by each group and used a dice to pick someone to tell me how Newton’s Laws support their design decisions. For the first time, I had several tables where students were hoping they would be the one picked because they were excited to talk about their group’s work, which was fantastic!

# Day 93: Whiteboards & More Whiteboards

AP Physics: Whiteboarding Angular Momentum

Thanks to a reminder from Dan Burns, I kicked class off with a clip from The Simpsons where Principal Skinner uses conservation of angular momentum to save Ralph. Afterwards, students whiteboarded and discussed yesterday’s problems. I focused on the conceptual problems, and I was pleased by how many students opted to use tools like SOS diagrams to guide their thinking, whether or not the problems asked for them. I also had some groups use analogies to linear momentum to answer questions since they found it easier to visualize. I got really excited when a couple of groups used Newton’s 3rd Law to solve one of the problems, though I didn’t think to take a photo of their boards.

Physical Science: Whiteboarding Motion Graphs

Students whiteboarded their video analysis results for constant velocity. This was the first time I’ve had them talking about graphs, and they made a lot of great observations. After the discussion, we used Logger Pro to look at a constant speed buggy in front of a motion detector and refine some some of the things we saw in the video analysis; after seeing me change the axes on the v vs. t graph from the motion detector, most groups looked at the scale on their v vs. t graphs and decided they should be horizontal lines. It was also fun to see the expressions on some faces when I found the slope of the buggy’s x vs. t graph and they saw it was the speed.

# Day 92: Angular Momentum & Motion Graphs

AP Physics: Angular Momentum

Students took a  quiz on conservation of momentum, then we finished yesterday’s discussion to introduce the idea of angular momentum. I showed them a Direct Measurement Video of two people on carts pushing off each other, followed by one of a rotating iPod to get a clear analogy for conservation of angular momentum. I think this would be worth taking the time to make a more student-centered discussion with students whiteboarding explanations next time around.

Physical Science: Motion Graphs

Students used Vernier Video Physics to do some simple video analysis of a mini hover disk and start looking at position vs. time and velocity vs. time graphs. I had them stay in Video Physics to view the graphs, but students are struggling to make sense of their graphs for constant velocity with the auto scale. I’m debating how I want to change it for next year. I’m leaning towards spending 1-2 days doing constant velocity with a low-tech, breadcrumb approach. I’d probably have students calculate the speed over each interval to make a velocity vs. time graph. Then, we can switch over to video analysis for constant acceleration.

# Day 62: Board Meeting & Energy Types

AP Physics: Board Meeting

Today, students whiteboarded the results of yesterday’s video analysis. Since my 2nd hour had quite a bit of discussion and worked through much of the sense-making while they were in the computer lab yesterday, I skipped some of the structure I’ve been using in board meetings and we got to the big ideas pretty quickly, which left time to whiteboard CERs of predictions for a demo that drops one marble straight down while launching a second horizontally. In my 2nd hour, I barely had to speak as the students spoke to each other and had some fantastic discussion that accomplished exactly what I hoped it would. In my 4th hour, my students were much more hesitant to speak up. They are a naturally quieter group and had a lot less dialogue in the computer lab, so I think they would have benefitted from some pre-discussion in their lab groups and a little more structure, like Casey Rutherford’s Observations, Claims, & Evidence which I’ve used to frame most of the board meetings this year.

Physical Science: Energy Types

We had some discussion about what seemed to be key characteristics of the energy types in yesterday’s simulation to form a basis for some definitions. I took a page from Modeling Instruction and defined potential energy as coming from interactions, then had some discussion about what constitutes an interaction. In the past, I’ve used stored energy as the definition for potential in 9th grade, but I like that interaction energy solidifies the connection between potential energy and forces.

# Day 61: Projectile Video Analysis & Energy Skate Park

AP Physics: Projectile Video Analysis

I gave students two videos of some students tossing a basketball and a video analysis guide I put together, then tasked them with getting the position vs. time and velocity vs. time graphs for each video of the basketball. I had a bunch of students who got genuinely excited when they looked at the velocity vs. time graphs and started putting together what they know so far to begin a model of projectile motion. One group even cheered when the slope of their y-velocity vs. time graph matched what their model so far!

Physical Science: Energy Skate Park

Students played with PhET’s Energy Skate Park simulation to look for how they could change the size of the various bars in the bar chart. Students pretty enthusiastically played with as many options as they could find, and made some nice observations, like how the motion of the skater changes when they switch to the moon or Jupiter.

# Day 66: Bouncy Balls & Molar Mass

Physics: Bouncy Ball Energy

Students worked on collecting data to determine whether a bouncy ball looses more energy while its in the air or when it hits the table. There are lots of different approaches, and groups spent the majority of their time trying to figure out what might be useful to measure, which lead to some great discussions. The most elegant approach I saw was a group that did some video analysis in Logger Pro and produced a position vs. time graph. They argued that since each bounce’s parabola is symmetrical, the bouncy ball must be at the same speed for a given height on that bounce, so the energy stays the same while its in the air. Then, they compared the steepness of the parabolas for each bounce to show that the energy changes after the bouncy ball impacts the table.

Chemistry: Molar Mass

Students practiced using electronic balances and switching between mass and moles. One of their tasks was to determine how many atoms of chalk it took to write their name on a lab table. The best part of today, however, was the ways I saw my students starting to come together as a class. I saw a lot of students, including some with a reputation for typically checking out in school, having great conversations about the quiz I returned or the day’s assignment. A few students even took over the whiteboard at the front of the room and started adding to what I’d put up there as they tried to make sense  of their measurements. I’ve been having a lot of conversations with these students about what effective collaboration looks like, since many have not really experienced it, and its great to see those conversations translating into the actions of my students.

# Day 44: Introducing Sound & Video Analysis

I was out for a field trip today, so no photos.

Physical Science: Introducing Sound

Students did some reading on sound waves today and started connecting it to what they’ve learned so far about waves in general.

Physics: Projectile Video Analysis

Students recorded videos of projectiles being thrown at different angles, then did some video analysis to see how that affects how high and how far the projectile travels.

# Day 43: Snakey Springs & Video Analysis

Physical Science: Snakey Springs

After getting a few vocabulary terms for waves, students got out the snakey springs to start looking for qualitative relationships between wavelength, frequency, and amplitude. I was surprised at how impressed students were when they realized a wave reflects off the end of the snakey spring; as I make the course more inquiry based, I’m reminded how easy it is to assume students have certain experiences or background knowledge they just don’t have.

Physics: Video Analysis

Our awesome tech guy got Logger Pro working on the netbook cart, so today I introduced students to doing video analysis. As a class, we walked through analyzing a video of a tennis ball tossed straight up in the air so students would have some idea of what the results should look like. Tomorrow, they’ll record and analyze their own videos.