Pedagogue Padawan 180

Today in AP Physics 2, students determined the mass of the electron. The students deflected an electron beam in a vacuum tube with the magnetic field of the solenoid. By measuring the current in the solenoid, the accelerating potential in the vacuum tube, and the radius of curvature of the electron beam, students were able to calculate the mass of the electron. There is a lot of uncertainty in the radius measurement, but the calculated mass is still fairly close to the expected value!

  ##magnetism ##practicumlab  

I always get a kick out of watching an entire class applying the right-hand rules during peer instruction, like today, a quiz, or an exam. I joke that they should stretch first so they don’t injure themselves with all the twisting and turning!

  ##magnetism ##peerinstruction  

Today I was off-campus for a meeting for our district’s Digital Learning Initiative (1:1 pilot). The AP Physics 2 students whiteboarded on their own. One of the problems I assigned was a bit more challenging that I realized requiring the application of the Law of Sines and an equation that we hadn’t seen previously. Probably not the best choice for what I wanted them to focus on.

  ##magnetism ##setbacks ##whiteboarding  

For one of today’s formative assessment sketches, I asked students to sketch the magnetic field of a current-carrying wire given the direction of current in the wire and draw the force vector on a positively charged particle near the current-carrying wire. I’m definitely gaining more insight into which students are still developing their understanding by seeing their sketches. I’m also better able to address minor issues and questions that I think I would normally miss. For example, some students wanted to draw lines between the x and dots representing the magnetic field of the current-carrying wire rather than just drawing the x and dots.

  ##magnetism  

After two days of school being closed due to extreme cold, we continued with the electromagnetism unit. One of my personal goals this semester is for more short, formative assessments focused on sketching and writing. Today, we spent time sketching magnetic field lines and magnetic field vectors generated by a current-carrying wire.

I displayed a few examples from students, and, as a class, we provided feedback on the strengths and weaknesses of the sketches.

  ##magnetism  

I ended class yesterday by inducing cognitive dissonance after asking in what direction a compass needle points, which pole is the colored end of the compass needle, and how magnetic poles interact with each other. I let them ponder the implications of those answers overnight. I started class today with the MinutePhysics video about the North Pole:

Once students are amazed at behavior of the various north poles of the Earth, we discuss how the magnetic poles have swapped over the course of the Earth’s history. I share this simulation image from NASA that shows what the Earth’s magnetic field normally looks like and may look like during a pole reversal:

  ##magnetism  

Today was our first day back after semester break. We are starting our magnetostatics and electromagnetism unit. After a brief introduction to magnetic fields, magnetic field vectors, and magnetic field lines, students explored seven different stations:

  ##magnetism ##activities  

Today is the first of three days of semester finals. AP Physics 2 students spent our final exam period exploring each others’ capstones and providing feedback. Since the capstones are published online, students are able to incorporate their peer feedback even though they have already “submitted” their capstones by submitting links via a Canvas assignment. Some students also took advantage of the time to review for their other final exams.

  ##capstones  

Today is the school’s official “review” day in preparation for finals which start tomorrow. Since the capstone projects are the final, we spent today wrapping up loose ends like surveys for the district’s Digital Learning Initiative (1:1 Chromebook pilot) and making sure everyone’s capstones were published. One student modeled a magnet falling through a copper pipe. We had some leftover liquid nitrogen and so we explored the affect of the temperature of the copper pipe on the rate at which the magnet falls. The colder pipe definitely resulted in a slower descent!

We had fun freezing various parts of students’ lunches as well. All was fun until the dewar accidentally got bumped off the table and broke. Loud bang, big mess, expensive replacement 🙁

  ##setbacks ##capstones  

Today is the last day for students to work on their capstones since they are due tonight. I’ll share some of the published capstones later. The in-progress capstone that I’m featuring today is a student who is performing a post mortem analysis on Physics Club’s recent high-altitude balloon launch. We’ve launched several high-altitude balloons in the past and our most recent launch was a couple of weeks ago. The payload encountered very high winds during flight and it appears that the tracking device became separated from the rest of the balloon and payload around 80,000 feet. As a result, we only recovered the tracking device and not the rest of the payload with our parachute, sensors, data, and video cameras. We are hopeful that someone will find the payload and give us a call as our name and phone number are on it. This capstone is modeling where the payload may have landed based on when the balloon burst. Lots of area to search!

  ##capstones