Heat Inquiry

For this week's inquiry experiment I used 4 identical coffee mugs, one cup of hot water, and covered each mug with a different material: a plastic Tupperware lid, plastic wrap, aluminum foil, and a potholder.  I thought that the potholder would prevent the greatest heat loss because of what I know about insulators and how we use potholders.  After thirty minutes, I measured the temperature of each mug.  To my surprise, the mug covered with the potholder was the coolest of all four, and the mug with aluminum foil ended up being the hottest. 

After doing a little research, I learned more about latent heat of vaporization and how evaporation causes cooling.  As the water evaporated from each mug, the different materials covering allowed for more or less evaporation.  The potholder absorbed a lot of the heat that was escaping, while the foil held it in.  The condensation on the foil may have even fallen back in the cup thus reducing the cooling effect.

I thought about this experiment this morning on my way to church.  I often put instant oatmeal in a coffee mug and take it with me in the car to eat on the go.  This morning my oatmeal was too hot to eat right away so I let it sit in the cupholder to cool a bit.  I began wondering how the temperature of the oatmeal would different from the water in my experiment if left to sit for 30 minutes.  Also, would oil hold heat longer than water? 

I enjoyed gaining a deeper level of understanding of heat and hope to convey this to my students as well.