For this week, students were asked to read Chapter 11.1 Household Magnets in How Thinks Work, the Physics of Everyday Life, and watch the following video by minutephysics.
I also reminded students they could be reading the Cartoon Guide to Physics, Chapters 12-19 for electricity and magnetism.
I started class with a bit of lecture about the previous chapter on electricity and then some on magnetism and how its similar (likes repel, opposites attract and the force depends strongly on distance) and how its different (you can have a postive charge all by itself, but so its impossible to have just a north pole, or just a south pole, they always come in pairs).
There were four activities involving magnets and magnetic fields for the lab. 1) Use magnetic filings to observe and sketch the magnetic field lines of various magnets.
2) Build an electromagnet – wrap wire around an iron nail and then attach the wire to a battery and see if you can pick up paper clips with your electromagnet. When students disconnect the battery the paper clips fall off the nail since its no longer magnetized.
3) Play Jishaku, a game where the first one to get rid of all their magnetic rocks win. Students take turn placing the rocks in the blue foam pictured below. The rocks are fairly strong magnets so if they are close enough the force between them will be strong enough to make them leap together. If the rocks come together then you add them back to your hand.
4) Play with Magic Penny Magnet Kit and the bottle of ferromagnetic fluid. The Magic Penny kit comes with two strong magnets (the silver bar below), some UK pennies and a book of tricks you can do with them.
I also showed the students an app, phET Interactive Simulations that is available on the App Store or Google Play and you can play with the simulations on your computer via a web browser. They have a number of nice ones for electricity, including John Travoltage, Balloons and Static Electricity, Charges and Fields, Ohm’s Law, etc. Its worth checking it out. These simulations give students a way to ‘see’ and play with charges and fields and concepts that can be hard to get across since they aren’t easily visible.