The Heat Is On!

For this week's experiment with heat transfer, I chose the following four materials to investigate as insulators: paper (paper towel), plastic (baggie), cloth (cotton dishrag), and aluminum foil. These materials were selected because of their different makeup of particles.  For example, the paper towel and cloth had tiny holes where air and heat could have escaped during the experiment.  The plastic had a very solid particle makeup, along with the aluminum foil.  I thought that the plastic would be the best insulator because it seemed to be able to create the tightest seal over the hot water. Upon conducting this experiment, I found that the aluminum foil worked as the best insulator to keep the water the warmest.  My hypothesis, the plastic baggie, came in second place.  The experiment's results made perfect sense because the whole purpose behind using aluminum foil is to keep hot foods warm and cold foods cool.

If I were to conduct this experiment again, I think that I would like to test out saran wrap as an insulator.  I think that it would be a good choice because it is used along the same lines as aluminum foil.  I also think that it would help to trap the heat and keep the water warm.  Another material that would be interesting to test would be rubber.  I have a rubber glove that I use to do dishes.  I wonder if the rubber would be a better insulator than the aluminum foil.  My hypothesis would be that the rubber is the thickest of the other insulators and would have more material to help insulate the hot water.  This would be an interesting extension to this lesson.

If I were to set this experiment up in my classroom, I would gather a bunch of materials that could potentially be used to test as insulators. I would set up the parameters the same, however I would introduce the experiment the day before and show the students the materials that I planned on providing.  To make this activity a little more fun and exciting, I would turn it into a competition telling the students that the group that can keep the water the hottest after thirty minutes will receive a prize.  Also, to engage them further, I would allow the students to bring in any insulating material that they have at home to use for the experiment.  This would provide the opportunity for those that are especially intrigued to go home and hunt for additional materials to test out.  Another way that I would make this relevant to the students' lives would be to set a purpose for the experiment.  I would type up a scenario that explains that reason for wanted to keep this water hot as long as possible.  A real world reason could include the delivery of soup to a sick person's house or even the delivery of a top secret liquid to a special science laboratory that is thirty minutes away.  As the liquid cools, it loses important enzymes and the students would need to deliver it as warm as possible.  These would be two possible situations that would give the students a purpose in this activity that has meaning.

From doing this activity, the students would learn what materials make good insulators, as well as the different ways that heat transfer occurs. More specifically, I would hope that the students would be able to apply this knowledge to their personal lives when needing to keep something hot. I also want to provide the students with hands on experiences that they can draw from when they are confronted with questions about conduction, convection current, radiation, insulators and conductors.  If the students can form these mental connections, the chances are greater that they will internalize the material and perform better on tests. We are just finishing up a study on heat transfer and I really think that my students have learned a lot because of the experiments and inquiry that have been done in the classroom.  For example, we checked different materials of hats to find the best insulator for your head.  This is a great extension to the above activity, especially to see if the material that insulates a mug the best is the same material that insulates your head most effectively.

In conclusion, this experiment taught me first-hand the insulating potential of different material.  It also intrigued me to ask questions and to make further extensions based on the initial inquiry.  Finally, it was easier for me to make connections when reading the definitions of conduction, convection current and radiation because I had seen some of the heat transfers in this experiment, especially conduction and the convection current. What a simple activity to produce so many additional discoveries and questions!