# Day 29: Board Meeting & Hurricanes

AP Physics: Board Meeting

Students whiteboarded their results from the 2nd Law Lab and we had a board meeting. Students needed a reminder to translate the equation for their lines of best fit into “physics terms”, but they are getting more skilled at that. I was also pleased with how quickly students picked up on things like which groups had similar slopes, which made it easy to build some ideas like why the slopes would change.

Earth Science: Hurricane Tracking

Students used some data from 1992’s Hurricane Andrew to plot its path and answer a few questions. They did a nice job connecting what they’ve learned about heat and wind so far to find some patterns in the hurricane’s path and wind speed, but the plotting took a long time. I’m debating whether I want to try and streamline the plotting next year so students can spend more time on the interpretation. It would be very easy to give them a completed map of the hurricane’s path, but I would need to revise or eliminate some of the questions where students paused their plotting to make predictions. Another option would be to put the map into Desmos as an image, then have students type in the coordinates. With the manual plotting, I overheard some conversations where students were connecting coordinates on the map to coordinates on a graph, which is a great connection for them to make and I can’t decide whether Desmos would help or hurt that connection. I also need to identify the key take-aways from this lab to help decide where I want students to spend their time.

# Day 28: Modified Atwood’s & Project Wrap-Up

AP Physics: Modified Atwood’s Machine

Students used a modified Atwood’s machine to collect data for a relationship between force and acceleration. We spent some time unpacking that statement since I’ve found it really isn’t obvious to students what that means; last year, a lot of students really struggled to go from that statement to recognizing they needed to change the force and measure acceleration,

Earth Science: Wind Turbine Wrap-Up

To conclude the wind turbine project, I gave students some information about an imaginary small farm and tasked them with selecting locations for three wind turbines and preparing a report for our “client” to justify their choice. Unfortunately, with the wind turbines and fans we have, it isn’t practical to set up both the topography and a trio of wind turbines for students to test their plans. Next year, I might try setting up a single, larger test area using a couple of our box fans so that we can have a big enough model for students to actually test their plan.

# Day 27: Elevators & Turbine Interference

AP Physics: Elevators

I showed students a video I made riding the elevator with a balance and asked them to determine whether the elevator was going up or going down and support their answer with free-body diagrams. I was pleased with how many groups started their conversation with “What’s our system?” I could tell from the conversations that a lot of students are still not entirely solid on the idea that an acceleration can be in the opposite direction of the motion, but thinking about the bowling ball lab from a few days ago seems to be helping. Next year, I want to do a better job of using the change in velocity arrows that show up in Etkina to help solidify the direction of acceleration.

Earth Science: Turbine Interference

In the next step towards designing a wind farm, students experimented with several turbines, comparing the amperage produced with different arrangements. This lab got my students asking some great questions that had me wishing that the trimester on physics came first rather than second this year. A lot wanted to know why the last turbine in a line wasn’t spinning, which is easy to explain with conservation of energy. A few others wanted to know what’s inside the turbine, which fits great with the build-a-motor lab we do in 9th grade physics. When we work on next year’s schedule, I’ll make sure to advocate for physics-earth-earth rather than this year’s earth-physics-earth sequence.

# Day 26: Defining Systems & Topography

AP Physics: Defining Systems

We played the mistakes game with yesterday’s free-body diagrams. In both my hours, there was some great discussion about a problem with a skydiver attached to a parachute and whether the upward force should be a tension force from the straps of the parachute or a normal force from the air on the parachute, which lead beautifully into the importance of defining your system.

Earth Science: Topography & Wind

As the next stage of their project to plan a wind farm, students built a simple “topography” using textbooks and used simple flags to make observations about how that impacted wind speeds. Afterwards, students tried placing a turbine at some of the locations where they’d left flags and measuring the current produced.

# Day 25: FBDs & Wind Maps

AP Physics: Free-Body Diagrams

I gave a short lecture on the types of forces, then had students work on drawing some free-body diagrams. I’m being really picky about including the interaction when labeling forces this year (i.e. Fg (Earth on object)) which I’m hoping will pay off in deciding whether a force should be there as well as with the 3rd law. There were some great conversations about which forces need to be accounted for as well as what causes an object to move forward after the force is done.

Earth Science: Wind Maps

Students used some maps to look for a relationship between average wind speeds and topography. Then, they picked what locations in Minnesota might make sense for a wind farm. This lead to some good conversations about trade-offs in engineering, such as why  there are some wind farms near big cities, even in parts of the state with relatively slow average wind speeds.

# Day 24: Bowling Balls & Problem Scoping

AP Physics: Bowling Balls

Students did a lab I borrowed from Frank Noschese hitting bowling balls with rubber mallets to look for a relationship between force and acceleration. I really like the conversations that happen when students are working out how to get a bowling ball to move at a constant velocity. When one group was wondering how to check, we ended up pulling out the Motion Shot app to make a motion map. Another group decided they needed to use gentle forward taps to maintain the constant velocity combined with even gentler backwards taps to counteract the forward ones; as they made their taps gentler and gentler, they eventually realized they could do away with them entirely. My 4th hour also got very excited about balancing things on their bowling balls.

Earth Science: Problem Scoping

On Thursday, students only had time to answer the problem scoping questions individually. Today, I had them answer the questions with their lab groups using a different colored pencil to differentiate individual ideas from group ideas. After that, we discussed as a class what kinds of things students will need to know for the engineering design challenge, which lead nicely into introducing and previewing the learning targets for the unit.

# Day 23: Test & Problem Scoping

AP Physics: Test

I use standards-based grading and this year, I’m giving each student two scores on each standard. What I’m calling the tier 1 score is from an assessment similar to what I gave in honors physics and the tier 2 score is from a full-period test with problems modeled on the AP Physics 1 exam. Today was the first tier 2 test. I’m not very focused today, so I spent too much time playing with a solution I made in Desmos to one of the multiple choice problems.

Earth Science: Problem Scoping

We’re starting a unit on wind that includes an engineering design challenge to plan a wind farm, so I decided to take a project-based learning approach to this unit. Today, I introduced the design challenge using a problem scoping process I picked up at EngrTEAMS. Students read a short memo from our “client”, then wrote individual answers to some questions about the specifics of the design challenge. We ran out of time for students to meet with their groups, so on Monday, they’ll share those answers in their groups and record a group answer in their notebook alongside the individual answers.

# Day 21: Angular Acceleration & Satellite Data

AP Physics: Angular Acceleration

This year, I’m embedding circular motion concepts as we wrap up their linear motion analogues, so today students took their first look at angular acceleration. Students used a Direct Measurement Video to plot angle vs. time for a disk with a rocket motor attached. Students were quick to notice their graph looked a lot like position vs. time for an object with linear acceleration, and were able to extrapolate a lot from there.

Earth Science: Satellite Data

Students looked at some images of cloud cover produced by NASA’s GOES satellite to make some claims about the cloud cover and associated weather in a few areas of North America. I didn’t use my evidence-based reasoning graphic organizer today, and I don’t think its a coincidence that many students just stated their claims without any evidence. I need to keep being explicit about what good reasoning looks like and stay on students to keep including that in answers.

# Day 20: Lab Practical & Clouds

AP Physics: Lab Practical

We started working on a constant acceleration lab practical today. A marble will roll down a track while a constant speed buggy drives past. Given the starting point of one, students need to find the starting position of the other such that the marble will land in a cup taped to the buggy. I had a couple of administrative things to deal with at the start of class, so we only got to collect the data students need to complete the calculation. I’ve got a computer lab reserved tomorrow, so we’ll test their calculations on Wednesday.

Earth Science: Clouds

Students were introduced to the different types of clouds today. I added some questions to focus on patterns in the names of the cloud types. Students were pretty successful at picking out the key roots and prefixes that show up in cloud names and reasoning out what they must mean.

# Day 19: Free Fall & Humidity

AP Physics: Free Fall

Students worked on plotting position vs. time using a Direct Measurement Video of five different spheres in free fall. This is the first year I’ve had students use uncertainty, and I’m finding I really like how it shapes conversations. A lot of students were looking for specific times in the video, then estimating the position of the sphere at those times, but a quick conversation about the large uncertainty that produces in position quickly got them to see the value in switching their approach.

Earth Science: Humidity Analogy

Students worked through some questions using beakers of water as an analogy for air at different temperatures and how that impacts humidity. It was pretty tricky for many students to predict what should happen to the water level when a given amount was moved to a larger or smaller beaker, so I think I’d like to get out actual beakers and water the next time I do this activity to make it a little more concrete. They did seem to get the analogy and were able to make some good predictions about humidity and dew points by the end of the hour.