After about a week of investigating circuits and the current model, we checked our understanding by presenting whiteboards of a series of problems. The discussion was okay and any mistakes were quickly identified. We do a lot of ranking problems followed by a discussion to justify the rankings. At this point, students only have the current model with which to apply, so several of these problems are more challenging than they would be if the voltage model was applied.
##whiteboarding ##circuits
This year in Honors Physics (a.k.a. AP Physics 1), we are using a combination of the Physics by Inquiry materials and the Modeling Instruction CASTLE materials. Our current model is based on the Physics by Inquiry investigations and the electric pressure (voltage) model is based on the Modeling Instruction CASTLE materials. I’m thoroughly enjoying the investigations that we are doing. Groups are engaged in careful observation and the construction of long chains of reasoning. I have the opportunity each class period to visit every group and have an in-depth discussion with each about their observations and conclusions. I ask each small group the necessary questions to expose their inconsistencies in their analysis and refine the model that they are constructing. Today, most groups analyzed the “pizza problem:”
In this exercise, students are asked to predict the brightness of bulb A and B when bulb C is removed. Unfortunately, most groups made predictions and then built the circuit to check their predictions. Their prediction for bulb A was correct, but most groups simply accepted that their prediction for bulb B was either right or wrong and didn’t carefully consider why. I had to ask several questions before these groups realized that they didn’t have a good explanation for why bulb B should be brighter or dimmer, and that was the point of the exercise – to expose the limitation of our current model. This is also why the circuit is called the pizza problem: “What is greater? Half of a large pizza or all of a small?”
Next year, I will explicitly instruct students not to build the circuit for this exercise, but instead throughly defend their prediction to each other and me. I think they will more easily recognize the limitation of the model when they can’t simply observe that bulb B is brighter in the actual circuit.
##circuits ##paradigmlab ##setbacks
In AP Computer Science, we are finishing our last unit before the AP exam. The summative lab is the Fractal Tree Lab. This year, students are provided much less direction. However, today, I did offer to work through the derivation of the algorithm with those students, who after working on it for most of day, wanted some assistance. They really just needed some help enumerating the key parameters for the recursive method and the geometry necessary to derive them. Here’s what we came up with:
I think the key idea is that the angle of the previous branch relative to the coordinate system needs to be passed as a parameter. This facilitates the calculation for the endpoints of the new branch. I’m excited to see if this year’s class is as creative as last year’s given that they have to struggle much more to derive the basic recursive algorithm.
##recursion
I love how some of my students continue to apply energy LOL diagrams long after we have finished the “energy” unit. In AP Physic B, we are in the midsts of an abbreviated particle physics unit. This group drew the LOL diagram for the collision of two high-energy protons creating a pion. The units for energy have changed to MeV, but the diagrammatic representation has not.
##particlephysics ##whiteboarding
In AP Physics B, we are in the middle of an abbreviated particle physics unit. Since we are so close to Fermilab, I feel compelled to introduce students to the history of particle physics and the organization of the Standard Model. Fermilab has a number of fantastic activities that are prelabs for the Particle Physics Masterclass. Today, we used data from the D-Zero detector to calculate the mass of the top quark. It is fantastic to use data from D-Zero and to walk through the identification and calculations involved in a collision event. It is also a great way to “trick” students into reviewing and practicing 2D conservation of momentum problems in preparation for the AP exam! The results were fantastic. The average of two classes of data was within 1 GeV of the mass of the top quark.
##practicumlab ##particlephysics
Today and Saturday, the team and I are on the campus of the University of Illinois for the State Science Olympiad competition. The students will compete in a huge variety of science and engineering events. I’ll help run one of them. The weather is fantastic and it looks to be a great weekend.
##local ##scioly
Today, we started the circuits unit in Honors Physics. We always start with the batteries and bulbs activity from the Minds of our Own video. In this activity, students are given a battery, light bulb, a piece of wire and instructed to light the bulb. Many students struggle to do this. I give everyone enough time to figure it out and to draw a diagram of four ways to accomplish the task as well as diagrams that are ineffective. We then watch the video and I congratulate them on bettering the Harvard and MIT graduates.
I’m really looking forward to this new circuits unit. My colleague who designed the unit has done an excellent job combining elements of the McDermott’s Physics by Inquiry materials and the CASTLE curriculum.
In addition to the battery and bulb activity, students made detailed and thorough observations of an incandescent lightbulb to determine how it works and why it is constructed the way it is. In past years, I’ve broken the glass bulb to make it easier for students to see the inner elements. This year, my colleague purchased 150 W bulbs with extremely clear glass. Students can observe the inner workings with the glass intact which makes handling and storing the bulbs so much easier.
##circuits ##paradigmlab ##equipment
A reflection technique that I learned from Scouting, is “Keep, Fix, Try.” Each year, we use this technique to reflect on the FIRST Robotics season.
The students demonstrate remarkable insight. In the past, their feedback has resulted in significant changes the next year that has elevated our team to where it is today. In consideration for the introverts among us, I always encourage students to submit their reflections offline and privately as well. I have received seven pages of reflection from graduating seniors in past years.
##local
A few summers ago, I had the pleasure of working at Fermilab on the Holometer Experiment. I wrote a series of posts attempting to explain the experiment. In my AP Physics B class, we take a day after finishing nuclear physics to share my experience with my students. The Holometer and the physics behind it are a great example of how much we don’t yet understand about our universe. I want students to appreciate that the field of physics is constantly changing and there is so much more to explore. Too often an introductory physics course presents the material in the context of 100-year-old, dead, white guys.
This past weekend, Huskie Robotics, FIRST Team 3061, competed at the Midwest Regional Competition. I am so proud of how the team performed. After qualification matches, we were ranked 7th, perhaps our highest ranking ever. During alliance selection, we became the captain of the fifth-seeded alliance where we selected teams 111 and 1781. Our alliance was defeated in the quarterfinal which was a disappointing end to our season.
However, the extraordinary efforts of several of our team members was recognized when we were awarded the Gracious Professionalism award for the assistance our team provided to other teams. This is the second time in three years that we have been awarded the Gracious Professionalism award. One of our team members spent considerable time assisting a rookie team. This rookie team was selected as the third robot on the first seeded alliance which won the regional. To show their appreciation, this team gave one of their championship medals to this student! This students efforts on the competition is illustrative of the culture we have tried to build over the years on our team, which makes me so proud. Furthermore, our mechanical lead Arpan was named as one of the Dean’s List finalists and will go to St. Louis to compete against other Dean’s List Finalists. Arapn has contributed so much to the team and FIRST over the past four years and this award is well deserved.
Our media team published a video blog for each of the three days of the Midwest Regional:
Midwest Regional Day #1 from Naperville North High School on Vimeo.
Midwest Regional Day #2 from Naperville North High School on Vimeo.
Midwest Regional Day 3 from Naperville North High School on Vimeo.
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