First Day of Class

I teach two sections of two classes each week. Monday and Thursday are with sophomores; Tuesday and Friday are with freshman and seniors.

In both classes, after reintroductions with the students we talked about where electricity comes from. I showed this slide:We talked a bit about how electricity is actually produced in each of these cases and which of these activities are considered sustainable. I told them that nuclear is not considered sustainable, but it is pretty clean compared to burning fossil fuels.

We split the groups into teams of 2 or 3 and gave each a LEGO motor, a wheel, a wire and and a lamp.

We demonstrated how spinning the wheel and motor in either direction would produce electricity.

I described how a motor works and we defined turbine as: A device that takes mechanical motion and converts it to electricity.

We discussed other inventions that used turbines: water wheels, dams, nuclear power plants, wind turbines and flashlights.

We challenged them to build a hand crank to power a light.

Before class on Monday, I tried to make a hand cranked dynamo light with LEGOs; but I could not find any platforms (the flat LEGO kind) to build on so it did not come out too sturdy. It proved it's uselessness when I presented it as an example and all of their hand cranks were as flimsy as mine. But on Tuesday, we had platforms, so I was able to show the kids how to make a sturdy two gear hand crank that worked. I'll start Thursday's class by showing how to build a proper hand crank.

I showed both classes how a gear chain works and we discussed how bicycles use the same thing. We talked about measuring circumference, diameter, radius and fractions.

They will build wind turbines in the next few weeks, so we talked about gear ratios for our projects. We decided that higher is better.

We also discussed other natural forces that produce power: hydro, solar, tidal. Luckily nobody asked me how solar is converted into electricity. I'm gonna have to go look it up after I post this.

On Tuesday, we had time to show this video where someone shows off a windmill made out of recycled materials.

On both days we closed the class by coming up with a definition of sustainable energy: producing energy with minimal long-term effect on the environment.

On Thursday and Friday the subjects are fundementals of electricity, circuits and voltage. We will use multimeters to measure how many volts their hand cranks produce. They will say "Hello World" with a simple LED breadboard circuit.

So far, the second section is much more difficult. The first section has less than 10 students who mostly seemed to be paying attention. The second section has at least 20 students. The seniors, and the female freshman are paying attention, but there are a few 14 yr old boys don't seem to be really listening. I have a hard time teaching when I am distracted by their distraction! There are only so many times I can yell "Hey!" without loosing my own train of thought. I'll have to figure out a way to deal with this. Advice in the comments, please.