Wednesday, February 15, 2012
This week we introduced a new topic: electricity. We started off by examining some batteries, taking note of things like voltage and the fact that every battery has a positive and a negative terminal. After a brief discussion about what batteries are and how they work, the kids made batteries out of grapefruit and strips of copper and zinc. Using a voltmeter we confirmed that our batteries worked. A single grapefruit has a voltage of around 1 v, which compared to your 1.5 v AAs is no small potatoes (FYI potatoes make great batteries too)! We attached wires to the battery, hooked up an LED, and NOTHING. Apparently 1 v is not enough voltage to power an LED. But, when life gives you lemons,make lemonade, or in my case, when life gives you a grapefruit tree, make several grapefruit batteries in series and voilà! Let there be light!