The older kids spent a lot of time today on electricity and magnetism - voltage probes and magnetic field sensors. We wired up solar panels to little motors and watched them spin. We tried running a miniature solar car, but the asphalt was too rough for the car to go very quickly. It was about 20 degrees cooler today though, than yesterday, so it was actually quite pleasant to be outside.
The little kids studied
rotational inertia - big words for a very simple activity... We built spinning tops. At first we tried making them out of cereal boxes and pencils, but that didn't work. The pencils were so long that they kept falling over. It's always a sinking feeling to a teacher when 5 minutes into a class, your lesson plan is a bust and you realize you've got 3 more hours to fill. Luckily, I had a box of K'nex pieces and they worked (phew).
The Chemistry Department is running a workshop for teachers this week in the building next door, so I took my kids for an afternoon break to watch the teachers test their experiments. I couldn't quite catch the action on this one, but when the teacher dropped Mentos mints into the 2-liter bottle of diet cola, the coke shot up like a geyser. After he got rid of all the coke, he filled the empty bottle with liquid Nitrogen, put the cap on, and threw it into the trash can. About 15 seconds later, the bottle exploded with a loud bang (I couldn't get a picture, because I was holding my hands over my ears). It not only blew the bottle apart, it blew the bottom out of the trash barrel. Glad I don't teach chemistry.
