Today, the students are off and we have an institute day. I was thrilled when I saw that the morning agenda included teachers sharing their instructional best practices with other teachers. Teachers could choose two of four sessions to attend. I quickly agreed to share peer instruction with my colleagues. A large part of my session was derived from Stephanie Chasteen’s materials from the Science Education Initiative at the University of Colorado. (Also, thanks to those of you who help me out yesterday on Twitter!)
Today we did the Simple Harmonic Motion Mathematic Computation lab from the Advanced Physics with Vernier: Mechanics lab manual. Students use a motion sensor to create a position vs. time graph, apply a sinusoidal curve fit, and then determine the relationship between the four coefficients of the equation and how to physically change the oscillator to affect those coefficients. It works really well and helps students better understand amplitude, offset, frequency, and phase. While motion detector baskets are sold from science suppliers, I found it cheaper to buy wire mesh bins for the local office supply company.
Last spring, I took eight of my computer science students to a Java competition. They had a good time and wanted to do more. I also had several students who were sophomores and juniors and wanted to do more programming even though there weren’t any additional classes. So, this fall, we founded a programming team. Earlier this fall, we entered the Zero Robotics competition, and our team is currently in the alliance competition phase. We also registered for the American Computer Science League and will participate in our first contest next week. Today, after school, I led them in a short tutorial of ACSL Assembly Language in preparation for the competition. They also just like to hang out in the lab after school.
Last year, I figured out how to construct a horizontal simple harmonic oscillator. It is a typical glider on an air track with two dynamics cart springs attached from the ends of the glider to the ends of the track. It works really well and provides a great lab activity as students begin to explore simple harmonic motion.
We restructured Honors Physics significantly this year. In previous years, reassessments were overwhelming at times. There were occasions where sixty students who show up after school for reassessments. This year, with our adjustments to the grading scale and standards-based grading, we have much more reasonable numbers. The students who should be reassessing are for the most part and those that don’t really need to aren’t. Yesterday afternoon had a typical turnout:
Today students calculated their predicted horizontal displacement based on the launch location they were assigned and taped their target to the floor (or desk, depending on location). Most groups’ predictions were not accurate. I haven’t reviewed each group’s analysis, but I know that one group suffered due to inaccurate data collected yesterday and another group had accurate data but analyzed it incorrectly. Next year, I may have groups use the short-range setting rather than the medium-range setting to reduce the velocity of the projectile and make the lab a bit easier. One group had solid data from multiple techniques, analyzed it multiple ways, determined which led to the most accurate initial velocity, and based their prediction upon that. They did fantastic:
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In preparation for tomorrow’s lab practicum, students designed their own experiments today to measure the velocity of the projectile fired from the launcher. Yesterday, when I introduced the lab practicum, I explained that they would have to predict where to place the target on the floor such that the projectile would hit it. The placement of the launcher wouldn’t be known until the day of the lab practicum. What they chose to measure today and how they chose to measure it was up to them. However, I encouraged them to consider measurement uncertainty and measure the velocity in at least two different ways. A couple of groups decided to use the pulse-timing mode in LoggerPro and two photogates.
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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!