Day 85: Electromagnetism

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.


Day 84: Earth’s Magnetic Field

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: