Today I’m featuring a student whose capstone is to investigate at what velocity a Nerf dart loses its stability in flight. Part of his investigation is to determine the drag force on the Nerf dart at various velocities. Huge thanks to my colleague for preparing the wind tunnel, which is used in the R&D classes, for this student!
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Today, I’m featuring a fantastic capstone. This student has used an Arduino to create an EMG sensor. He’s attempting to characterize the signal such that he can determine the amount of weight being lifted based on the signal from the EMG. Really cool biophysics application!
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Today, I’m featuring one student who is calculating how many balloons would be required to lift a house as done in the movie Up!. We had some leftover helium from our recent high-altitutude balloon. I like his approach which starts with filling 13 balloons with helium and connecting them to a force sensor.
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AP Physics 2 students continued to work on their capstones. Today, I’ll feature one student’s capstone which is essentially a paradigm lab for an electric motor. We won’t study electromagnetism or electromagnetic induction until next semester. He saw a video showing how to build an eclectic motor and wanted to determine what affected the rotation of the armature. Maybe we’ll use his capstone when we investigate electric motors next semester. I like how he is using a photogate to measure the rotation of the armature.
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Today, AP Physics 2 students had their first day of in-class work on their capstones. They must submit their initial idea by the end of the day tomorrow. I’ve already heard so many fantastic ideas. This year’s capstones should be amazing and really varied. Usually I have to sign out the laptop cart of iPads all week for student research and work. This year, most can use their Chromebooks. Those students doing video analysis need a laptop.
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I was off campus today at the annual AP Science Symposium while my AP Physics 2 student finished their circuits exam. I am fortunate that a nearby high school hosts an annual AP Science Symposium. This year, nearly 30 AP Physics teachers attended. It is fantastic to spend the day asking questions, listening, and sharing with peers from other high schools. I was pleasantly surprised at how interested and receptive the other AP physics teachers were to Modeling Instruction (historically the philosophy of these teachers hasn’t aligned much with Modeling Instruction). I think the new AP Physics 1/2 courses and their emphasis on deep conceptual understanding has created this opportunity. My colleague shared his recent experience administering a goalless lab practicum, which is an idea I have to try!
##ap ##modphys
Today, we did some peer instruction of conceptual circuits questions as a review before the multiple choice portion of the exam. Due to short periods tomorrow, I moved the multiple choice portion of the circuits exam to today. The question that generated the best discussion was this one:
Listening to the justifications, I realized that the values specified in the question have the potential to leave students with a misunderstanding. Some groups discussed how after the switch is flipped the two capacitors have to end up with the same charge. They didn’t appreciate that, while their answer was correct, the two capacitors only have the same charge because they have the same capacitance. The correct justification is that the two capacitors must have the same potential difference after the switch is flipped and current has stopped flowing. This realization is a result of the peer instruction discussions that I listen to. If I simply looked at answers, I wouldn’t have realized that students didn’t correctly understand the answer to this question. I’ll change this question for next time!
##peerinstruction ##circuits
In AP Physics 2, we didn’t have time after a practice quiz for a series of peer instruction conceptual questions. However, I did share one of the more challenging next-time questions:
Students worked independently for a few minutes to answer the question. I then had them discuss in table groups their answers and work on their justifications. Finally, we discussed as a whole class. I particularly like this questions, because it shows that it is easier to prove that if current was to flow through the middle LED that an inconsistency results rather than proving that current cannot flow through the middle LED.
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Today, I was out of the classroom for professional development related to our district’s 1:1 digital learning initiative. AP Physics 2 students whiteboarded the final set of circuits problems. One positive aspect of the professional development was that half of the time was set aside for us participants to define our own topics in an edcamp style. Within minutes, we had eight different sessions with facilitators and participants scheduled!
Today we discussed the results from Friday’s activity modeling the capacitors in series and in parallel. Historically, students have struggled to understand why capacitors in series must all have the same charge. This year, many more students appear to understand this concept. I think what has helped this year is the continued focus on connecting observed macroscopic phenomenon with atomic-level behavior. Visualizing a positive charge carrier flowing onto the positive plate of a capacitor and repelling another positive charge carrier from the corresponding negative plate, and then that positive charge carrier flowing onto the positive plate of the next capacitor in series, and so on, facilitates the observed phenomenon that capacitors in series have the same charge.
Sorry about this week. It was rough, and I was gone two days and took few photos.
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