Tuesday, January 27, 2009

Conduction






















We have begun to investigate Heat Transfer. We began with conduction - the movement of heat energy through solids by molecules bumping into each other. We started off by learning how to safely light a match and then a candle. Proper safety precautions were reviewed and practiced. Our first experiment was called "Hot Chocolate." The students placed 5, small chocolate bits on an aluminum "bridge." They placed a candle under the middle of the bridge, lit it, and timed how long it took for the bits to show signs of melting.







We then did an experiment called. "Heat Race" where we investigated if different metals conduct heat at the same rate. We used brass, iron, and copper wires. We measured and marked 2 spots on the wires 5 cm apart and placed a chocolate bit on one of the spots. We placed the candle under the other spot 5cm away, lit the candle, and time how long it took for the chocolate bit to show signs of melting. We did 3 trails for each wire and recorded the information on a data chart. This experiment culminated with a formal, written lab report.







To review what we learned about conduction, we did two demonstrations. One was with thermal conductivity bars placed into hot water and the other was with a heat conductometer - a devise with 5 different metal spokes.







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