This week I completed an investigation about heat transfer. I used four cups of the same size as well as four different materials (aluminum foil, wax paper, plastic sandwich bag, and newspaper). The objective of this was to find out about their insulation abilities and how well they keep conduction from occurring.
The heat transfer method that the materials I used were trying to discourage was conduction. I know this because "anytime there is a temperature difference, there is a natural transfer of heat from the region of higher temperature (in the cup) to the region of lower temperature (outside the cup)" (Tillery, Enger, & Ross, 2011, p. 86).
However, convection was occurring within the cup. "Molecules with higher kinetic energy are moved from one place to another, creating a cycle as one cools and one warms" (Tillery, Enger, & Ross, 2011, p. 87).
I believe that both are occurring during this experiment. "Conduction occurs primarily in solids, but convection happens only in liquids and gases, where fluid motion can carry molecules with higher kinetic energy over a distance" (Tillery, Enger, & Ross, 2011, p. 87). However, during this experiment I placed a solid between the two bodies of gases.
Other materials that I may have chosen for this experiment would be cotton wool, styrofoam, or sponge. "Most insulating materials are good insulators because they contain many small air spaces" (Tillery, Enger, & Ross, 2011, p. 87). Even though I found that the aluminum foil was the best insulator out of all the materials that I tried, I believe that adding styrofoam between the aluminum foil would be a really good insulator because of it's air spaces.
Other items that I would like to try are corn on the cob. It seems to radiate heat for a long period of time and it would be interesting to see what could keep it warm the longest. I would also like to try keeping ice as cold as possible, so to try the reverse, to keep the heat from getting in to it.
If I were to set this experiment up for my students, I would probably use the same approach. I like how there was some structure, for example, we had to use four of the same cups and cover the top with a material that we chose and seal with a rubber band. However, I would encourage more research about good insulation materials. Perhaps I would not limit them to only covering the top, but also leave it to them to decide if they cover the whole thing or just the top.
In order to make it fun for them, I would make it into an engineering project instead of an investigation. Like the lesson plan in this week's resources for students to create ice cream containers, my students could do something similar.
Heat is a relevant topic to students lives. One way that I could make it even more so would be to discuss with them about leaving car windows up in the summer and how the heat continues to grow in there. The car windows and interior serve as insulators, not allowing the sun's heat to leave the car. We would discuss the dangers of leaving children and animals in a car during hot weather. Another thing we could discuss is food containers and cooking which is something every child likes to discuss. If I were teaching a class on energy, I may discuss with students about energy efficiency in the home with heating. Students could design an energy efficient home with insulated windows, walls, etc...
I would like my students to understand at the end of this lesson that heat is an energy transfer between two bodies and that it can be transferred three ways. Not only can it be transferred, but there are ways to keep the heat from being transferred when it is needed where it is.
References:
Tillery, B. W., Enger, E. D., & Ross, F. C. (2008). Integrated science (4th ed.). New York, NY: McGraw-Hill.
However, convection was occurring within the cup. "Molecules with higher kinetic energy are moved from one place to another, creating a cycle as one cools and one warms" (Tillery, Enger, & Ross, 2011, p. 87).
I believe that both are occurring during this experiment. "Conduction occurs primarily in solids, but convection happens only in liquids and gases, where fluid motion can carry molecules with higher kinetic energy over a distance" (Tillery, Enger, & Ross, 2011, p. 87). However, during this experiment I placed a solid between the two bodies of gases.
Other materials that I may have chosen for this experiment would be cotton wool, styrofoam, or sponge. "Most insulating materials are good insulators because they contain many small air spaces" (Tillery, Enger, & Ross, 2011, p. 87). Even though I found that the aluminum foil was the best insulator out of all the materials that I tried, I believe that adding styrofoam between the aluminum foil would be a really good insulator because of it's air spaces.
In order to make it fun for them, I would make it into an engineering project instead of an investigation. Like the lesson plan in this week's resources for students to create ice cream containers, my students could do something similar.
Heat is a relevant topic to students lives. One way that I could make it even more so would be to discuss with them about leaving car windows up in the summer and how the heat continues to grow in there. The car windows and interior serve as insulators, not allowing the sun's heat to leave the car. We would discuss the dangers of leaving children and animals in a car during hot weather. Another thing we could discuss is food containers and cooking which is something every child likes to discuss. If I were teaching a class on energy, I may discuss with students about energy efficiency in the home with heating. Students could design an energy efficient home with insulated windows, walls, etc...
I would like my students to understand at the end of this lesson that heat is an energy transfer between two bodies and that it can be transferred three ways. Not only can it be transferred, but there are ways to keep the heat from being transferred when it is needed where it is.
References:
Tillery, B. W., Enger, E. D., & Ross, F. C. (2008). Integrated science (4th ed.). New York, NY: McGraw-Hill.
Wow! What a great lay-out you have for your blog. I especially enjoyed all the pictures you posted. I love the idea you had about the car windows and how the heat gets trapped. I think that would be a great topic to discuss with the students. They often talk about how hot the summers are here in the Inland Empire of California, and when the air conditioner is not working in the classrooms, the complaints never stop. I also loved the idea of teaching about heat transfer and energy efficiency. It is splattered all over our society...how efficient technology has become.
ReplyDeleteThanks for such an informative blog and for all your creative ideas!
Janice,
ReplyDeleteExcellent observations and synthesis of the information. I really enjoyed your blog.
When discussing the convection that is occuring, it could also be explained that the heated molecules are less dense and rise, whereas the cold molecules are dense, sinking. This concept ties in with several science topics, such as the development of air masses and rock formation.
Also, I love the idea of using corn on the cob. I wonder how our students could devise a way to make that happen.