Day 151: Rate of Dry Ice Sublimation

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Students in IS I calculated the rate of sublimation of chunks of dry ice. For the longest time there was only one location in our county to purchase dry ice (local dairy main offices) and now we have to get it in the county to our west (Lancaster). We have to have a commuting teacher pick it up. Students enjoyed observing the dry ice in a beaker of warm water. They used the phase diagram to figure out the behavior of dry ice. They used Logger Pro to graph mass vs time and used the slope to come up with a sublimation rate in g/sec.




Day 150: Physics – Project Based Learning


OK, I admit that this photo is not of my class. My classes did more of the same today so photos would just be repeats. I had reason to stop by a colleagues class to see his Honor Physics students working on their own Van de Graaff generators. They even had a full-size drill press set up in the classroom. The pressure was on as the device HAD to work. Loved to see a student wearing his miniTHON shirt nearly two months after the event! Can’t wait for miniTHON2015.

Day 147: Planet Configurations – Inferior Vocabulary

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Students in astronomy were introduced to the confusing vocabulary of planetary configurations. Inferior vs. superior planets goes just fine, but things get troublesome when they find that an inferior planet can be in inferior conjunction or superior conjunction and that a superior planet can be in conjunction (note no inferior or superior here) or opposition. This simulation from U of Nebraska-Lincoln helps a lot.

Day 146: Ptolemy, Kepler, and Homer (Simpson)


As the astronomy students are introduced to Kepler’s Laws of Planetary motion, they learn how to draw ellipses and calculate eccentricity. They do some light reading on Ptolemy’s geocentric view of the universe and his epicycles. This gives me a chance to show the video clip below (showing epicycles can be used to explain just about any movement, right or wrong).

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