Science in the Library

On May 19, 2017, kids came to the Pasadena Public Library to make wind turbines that would generate electricity by turning the shaft of a hobby motor. We were inspired by a project we found at https://www.exploratorium.edu/snacks/light-wind . The goal was to use the motors in reverse--instead of the electricity making the shaft turn, the turning would make electricity! We hoped to produce enough energy to light an LED bulb attached to the motor. It didn't work out that way, but we still made a great science lesson of it. I provided several different motors, but every time I tested them myself, I could not get the LED light bulb to come on. One kind of motor I got at Fry's was just too strong to turn in the wind. It probably would have needed blades several feet long and a floor fan wasn't going to produce enough wind. The other kind turned easily , but didn't generate quite enough voltage. (One of the kids accurately noted: "Don't you need more energy to op...

For today's Curiosity Machine classes, our last meeting of the four-week session, we did an exciting project from the Curiosity Machine website: balloon helicopters ! We learned about different kinds of energy, particularly elastic potential energy. Elastic potential energy is the potential energy stored when you bend, stretch or deform an object, and that energy converts to kinetic energy as the object bounces back. Here's a great website that explains it pretty well: Physics 20 Project . We discussed examples of elastic potential energy using a Family Feud presentation I made on Scratch. You can click on the image below to see the project, though it's supposed to be used as a tool for discussion: The project itself was challenging and I'm glad I worked on my sample ahead of time. But it's so exciting to see those balloons fly! First, you have to cut a boba straw to about the same length as the rubber band you plan to use (when it's at equilibriu...

Today's project was designing a wind-powered water pump! We discussed the history of harnessing the wind to power machines, from Hero of Alexandria's wind-powered pipe organ in the 1st century A.D. to the wind pumps used in Muslim cultures in the Middle East and Central Asia, to the windmills created by the Dutch (which--I didn't know before--could mill grain AND pump water from the ground!). The book I mentioned in our discussion today was called Wind Power , written by Ian Graham and published by Raintree Steck-Vaughn Publishers. We talked about Daniel Halladay, the American inventor of the wind pumps used in farms across America. We talked about the Law of Conservation of Energy, how energy is never created or destroyed, but only changes form--in this case, changing from kinetic energy to mechanical energy, and in wind turbines that power homes, it is also converted to electrical energy. We talked about converting different kinds of motion using a mach...