The Heat Is On

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.

Engaging in Guided Inquiry

          I have been on a trip with my family and have been away from home, so a lot of improvisation had to occur in order for me to complete this assignment.  It just goes to show that guided inquiry does not have to be complex, not all the materials need to be provided for you in a kit, and you need to be innovative. Inquiry does not have to be expensive, but it does have to be engaging.  After thinking about the list of questions, the situation I was in, and what would be the most interesting to me, I finally selected one: How do different surfaces affect the momentum of marbles?

            Now, in the hotel room, I did not have a meter stick so I used the palm of my hand for measurement, which I knew was pretty close to 10 centimeters and my pinkie nail, which is 1 cm exactly.  I set up the ironing board against a bureau in the room and propped it against the desk. I also placed the ironing board at a 30 degree angle so it would be able to gain velocity consistently with the large and small marble before it went across the testing materials.  Then, I took the idea from the video I watched this week and I put the hotel resource binder as a barrier at the one meter point from the end of the runway for the marble to hit.  I also thought about what types of surfaces I could use from the hotel room.  I selected a sheet, a wooden desk, newspapers, and a towel.  These were four very good materials of different textures, even though the newspapers didn’t really work that well.  My hypothesis at the beginning of the experiment was: I think that the bumpier surface will slow the marbles down faster, but the smaller marble will be affected by the surface the most.  When I released each marble, I watched to see how many times it would hit point 1 (the barrier) and point 2 (the ironing board).  If it didn’t reach, I would measure the best I could, and even though it was not a meter stick, I could still see a pattern in my data.

What went well during the experiment?  What did not work well?  The ironing board was slightly bent so it made the marble go to the right a bit and so I had to compensate by setting the marble over more to the left.  The newspaper did not work as well as I had thought because of the creases in the middle affecting the momentum of the marble.  The towel worked really well and so did the sheet and desktop.  The data I collected was reliable and accurate.  I found that the towel stopped the large marble faster than any other surface and the large marble travelled further on the smooth surface of the desk as well.  I also found the small marble got slowed down by the surfaces much faster.  I would say that this was a very successful experiment and it helped me to answer the question well.  I wish I had other materials to try, but I am confident that the outcomes would stay the same.

What modifications would you make to this experiment to get a different or modified result?   I would like to try more materials like sandpaper or wax paper.  I would also make sure that I had a meter stick and perhaps more space so that there does not have to be a barrier to stop the marbles.  

How might you set up this or a similar experiment for students in your classroom?  How could you make this experiment more fun, interesting, or engaging for your students?  How might you design this experiment so that it is relevant to students' lives?  I might actually set up this experiment for students differently, but still I would have an incline for them to use with the marbles.  What I did this year with my students to test how the mass and size of an object affects the speed. I may continue to use this experiment question, but frame it around momentum instead of speed. They would use tennis balls, ping pong balls, styrofoam balls, large marbles and small marbles.  This would allow them multiple opportunities to test many sizes and masses because they often think the bigger it is, the faster it will go, but what about the large styrofoam ball?  It would really get them to think.  To relate this to students' lives, I would have them investigate the affects of larger massed vehicles versus smaller massed vehicles in car accidents, and how much stopping time they both need in order to make a safe stop.  
What specifically would you like students to learn from this experiment?  Did you achieve this goal? I would like my students to learn that the larger the mass, the more the momentum.  The faster an object, the more the momentum as well.  I would also like them to apply it to their own lives when playing sports, riding in automobiles, riding bikes in order to stay safe.