The Heat Is On

To conduct this experiment, I used some random materials I had lying around in my kitchen. I used styrofoam, aluminum foil, a cloth (used to wash dishes), and a piece of plastic. I chose styrofoam because I know it can serve as a great insulator for cups of hot coffee. I did realize, however, that in this experiment, the hot water was in a mug and the styrofoam was only used as a cover. I knew going into the experiment that this meant the styrofoam may not perform at the level I thought it could have as an insulator. I chose aluminum foil because I know I have used aluminum to cook and I can touch it almost immediately after removing it from a heat source, showing its ability to resist changes in temperature.

I used four mugs (unfortunately I did not have four completely identical mugs) and filled each with one cup of water that had been heated in the microwave for forty-five seconds. Each mug of water measured at one hundred and six degrees Fahrenheit prior to being covered. The styrofoam posed a problem because it was a plate. I was unable to secure it with a rubber band over the top of the mug.

Results:
Styrofoam began at 106 degrees, ended at 82 degrees (-24)
Aluminum foil began at 106 degrees, ended at 90 degrees (-16)
Cloth began at 106 degrees, ended at 88 degrees (-18)
Platic began at 106 degrees, ended at 92 degrees (14)

If I were to set this experiment up for students in my lab, I would keep the guided-inquiry format. I would give them the problem to solve, which is to determine which material makes the best insulator. I would provide them with a wide variety of supplies and materials and let them design the set-up themselves. They would hopefully realize the value of changing only one variable at a time. This means they would have to use the same object to hold the heated material and keep the temperature constant at the start for each test. They would have to keep the time constant as well as the location of the mugs.

To make the experiment more relevant to their lives, I would have them do a follow up activity based on one of the following prompts:
-You are a product designer that is in charge of coming up with a new line of pots and pans that will heat substances the fastest. What type of material would you use in your design and why?
-You work for a major fast food corporation and are given the task of redesigning the coffee cups so that they keep the coffee warmer longer. What materials would you use and why? Would this be cost effective?
-You are about to invest in a reusable beverage container. You will use it for both hot and cold beverages. Which container will you purchase and why?

I would like students to walk away from the experiment feeling like they learned something practical that they could take with them from day to day in their own lives. The information they gathered can be useful to them as consumers later in life. I also would like my studnets to come away from this activity feeling as though they played a major part in the design of the experiment. This should make them proud of their results and confident when sharing them with others.