Wednesday, December 15, 2010

Heat Transfer

Heat can transfer through conduction, convection, or radiation (Tillery, 2008).  Conduction is the transfer of heat by or through the means of a conductor. Convection is the circulatory motion that occurs in a fluid at a no uniform temperature. Radiation is emitting radiant energy in the form of waves or particle means by rays.
Prior to beginning the experiment, I gathered all materials (four mugs, a measuring cup, thermometer, a clock, a cotton sock, a plastic zip loc bag, aluminum foil, and a coffee filter). Next, I made a hypothesis that the cotton sock would make the best insulator. In an effort to achieve maximum results on equal starting water temperature, my husband assisted me with filling the mugs to the marked line. The starting temperature was 117˚ degrees Fahrenheit and we both covered two mugs and started the clock. After thirty minutes had passed, I removed all four substances and recorded my results in the chart below:
Substance
Temperature
Aluminum Foil
99˚F
Coffee Filter
102˚F
Cotton Sock
100˚F
Zip-Loc Bag
105˚F

* The starting temperature was 117˚ degrees.
The zip-loc bag makes the best insulator if these four substances are considered.
If I was to repeat the experiment, I would have chosen items such as paper, a silk scarf, and a wool sock. I would allow my students to conduct this experiment using warm or cold water, to reduce potential hot water hazards.

3 comments:

  1. Sandra,
    It is interesting the actual difference in temperatures you got. Mine were all so similar. What type of mug did you use?

    -Julie

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  2. Same results! Love the ziplock bag though - had not thought of using that one! Great work sandra!
    dave

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  3. Thanks Dave. Julie, I used the one cup fiberglass mugs. I am not sure as to how much it helped that my husband filled two mugs and covered them while I filled and covered the other two for the purpose of achieving the same temperature for each mug.

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