I like this time of year. Students are comfortable in class, procedures have been established, confidence is increasing, and things are running smoothly. One example is students are writing themselves better feedback on quizzes. I learned of this technique from Frank Noschese. When a student is done with a quiz, they get up and head to the back lab tables where they consult the key and write themselves comments in an orange marker. The purpose is for them to reflect on their thoughts immediately after completing the quiz and capture this reflection in feedback to themselves. I usually still collect the quizzes, read their feedback, and write my own. While I encourage them not to focus on correcting their quiz, many do, but at least most of them also capture some other thoughts.
Whiteboarding the projectile-motion problems has the potential to be less engaging because many students find these problems easy because they are an application of existing models which which they are familiar. To keep whiteboarding interesting, I introduced the Mistake Game today. Students came up with several believable mistakes to hide on their whiteboards. Here is one where they didn’t use the components of the velocity:
I also want to share this whiteboard which presented the independent of the horizontal and vertical motion so clearly:
We have our own unique twist on the traditional monkey-and-hunter demonstration. My colleague developed a narrative that focuses on Anti-Curious George:
The story is that Anti-Curious George was produced a Fermilab where they can make antimatter. (I usually get on a bit of a tangent about Fermilab, particle colliders, and high-energy physics.) Anti-Curious George is curious like his counterpart, but unlike his counterpart, he is not basically good, he is evil. Our job is to capture him by shooting him with the tranquilizer gun. We share that we know from careful observation that Anti-Curious George will drop from the tree when we fire our gun. The question posed to the students is where to aim. Very few (usually none) predict that we should aim right at Anti-Curious George.
After the surprising result of the demonstration, I challenge the students to explain conceptually why we should aim right at the target. This is not easy and it was a few years before I developed a solid conceptual explanation that students would grasp. I also refer them to a problem in the text in which they can prove algebraically why this works. (First time I’ve referenced the text this year.) Tomorrow, we will discuss the outcome of this conceptually and algebraic challenge!
Today I did what I should probably do more often, I kept my mouth shut. I told my Honors Physics class that they were going to prepare and present whiteboards of their video analysis of projectile motion from yesterday and define a general model for a ball thrown through the air. Furthermore, I wasn’t going to contribute to or guide the discussion. It was totally up to them.
I managed to keep my mouth shut and they managed to have the best whiteboarding discussion of the year. Their comments, questions, insights, and leadership were great. I took notes the whole time and will try to turn them into a blog post. More than once I cringed as it appeared the discussion was heading off the rails but each time someone stepped up with a great question or comment and brought the class back on track.
At the end of class, they gave me their model summary:
When I asked about motion graphs and mathematical models, they explained that there was no point to draw them. “We identified the balanced forces / constant velocity and unbalanced forces / constant acceleration models. Why draw the graphs again; we all know those models.” Nice.
##pmm ##whiteboarding ##paradigmlab
Today, we started modeling projectile motion in Honors Physics. We filmed three examples of a ball being thrown and groups analyzed the videos using LoggerPro. I shared with students that they are ready to define this model without any assistance from me. Tomorrow, each group will present present their graphical and mathematical model and the class will define a general model for projectile model without any input from me!
Today in AP Physics B, we whiteboarded problems in preparation for tomorrow’s thermodynamics exam. One problem was from Giancoli (5th Edition), Chapter 15, problem 53 which reads: When 5.30e4 J of heat are added to a bass enclosed in a cylinder fitting with a light frictionless piston maintained at atmospheric pressure, the volume is observed to increase from 1.9 m3 to 4.1 m3. Calculate (a) the work done by the bass, and (b) the change in internal energy of the bass. (c) Graph this process on a PV diagram. Here’s their solution:
The answers matched the back of the book and make sense in terms of the calculations, but something didn’t sit right with me. I hoped one of the students would ask about it, but since no one did, I asked if we would expect the internal energy of the gas to increase or decrease based on the PV diagram. Since the pressure is constant and the volume is increasing, the internal energy must increase. However, based on the values supplied and the first law of thermodynamics, the change in internal energy is negative. After discussing, we decided that the values provided in the problem were just inconsistent and that the heat added to the gas should have been much larger. Are we right? Did I overlook something?
As I captured before, 42 junior-high students have been working with their high school mentors to design, construct, and test underwater remote-operated vehicles (ROVs). Over the past several weeks, they have completed their designs, cut PVC pipe, glued together their frame, and mounted their motors. This week most groups were installing switches in their control box and wiring the switches and motors. They still have a lot of work to do, but we hope to see some ROVs in the water in a couple of weeks!