Heat Transfer Experiment

Material Selected

The materials I used for the heat transfer experiment were aluminum foil, a paper towel, packing foam, and paper insulation.  The reason I chose them was because the directions said chose some materials you think will work well and some you think will not.  I thought the paper towel would not work well, but I thought the others would.  I used a laser thermometer because the thermometer in my science kit was broken.

Results

The following are my results

Insulator	Beginning Temperature	Ending Temperature	Temperature Change
packing foam	67.8°C	49.8°C	-18°C
aluminum foil	66.9°C	50.1°C	-16.8°C
paper towel	62.3°C	44.1°C	-18.2°C
insulation paper	60.6°C	43.4°C	-17.2°C

I found that the foil did the best job and the paper towel performed the worst.  I guess I should have known the foil would do the best since it is used to cover food to keep it warm.  I think the paper insulation would have worked better, but I could not get it to form a tight seal around the mug.

Similar Experiment for Students

To make this experiment more interesting for students, I think I would do two things.  First, I would let students choose the material they want to test.  I find that when students are given a chance to think creatively, they usually do a great job and come up with ideas.  Next, I would make it a contest to see who could come up with the best idea.  My students are very competitive and seem to be more enthusiastic when they are racing against each other.

I might also borrow ideas that I read from our discussion.  We could see which group could devise something to keep an ice cube from melting the longest.  This could be relevant to students’ lives because they bring their lunches, and they could benefit from finding ways to keep cold things cold.

Another way to conduct the experiment would be to ask local contractors to provide samples of insulation material.  We could test them to see which ones would work best with the mug experiment or the ice cube.

Student Learning

As with any activity we do in class, I like for my students to see that science touches so many parts of their lives.  Also, I like them to work like real scientists and to do things that have real-world applications.  Without theses applications, it seems more like we are just “killing time” than we are seeing how science is relevant to their lives.

Guided Inquiry - Working with Pendulums

Does the mass of an object affect its momentum?  One way to test this idea is to experiment with pendulums.  The experiment I chose was to find out if a lighter or heavier pendulum comes to rest more quickly.  In order to complete this activity, I engaged the help of my husband and son.  The first thing we had to do was find a place to hang the pendulum.  As a family, we enjoy doing experiments and building things so we utilized two eyehooks that are in our basement ceiling.  We used a spool of string that has a kite hook at the end.  We selected washers with three different masses.  We confirmed the mass of the washers by using a digital scale.  The first challenge we encountered was that we made the string too long.  The pendulum was swinging for a very long time.  We decided to shorten the string to two feet from the ceiling.  The next problem we encountered was deciding what constituted the pendulum stopping.  After a few test runs, we realized that the pendulum could swing for a fairly long time.  We decided to put a box under the pendulum.  On the box we drew a circle with a three inch diameter.  We decided that once the pendulum was swinging within the circle we would consider that the end of the trial.  Each time we did the experiment we pulled the pendulum back to a height of fifty-seven inches.  We did this so that we were sure to test only one variable, the mass of the pendulum.  Here are a few pictures of our set up.

As we put the experiment together, we discussed possible outcomes.  The two ideas we came up with were that the pendulum with greater mass would have more momentum and would therefore swing longer.  The other idea we had was that the washer with a greater mass would be more affected by gravity which would cause it to swing a shorter period of time.  After we tested the three pre-selected washers and then we decided to put all three washers on the hook to see what would happen.  The following is the data we collected.

Weight of Washer(s)	Swing Time
59 grams (three washers)	7:57 minutes
34 grams (one washer)	4:58 minutes
20 grams (one washer)	4:11 minutes
5 grams (one washer)	2:21 minutes

From our data we discovered that the greater the mass of the pendulum the longer the swing time.   We decided that the mass of the pendulum affects its momentum. 

           

If I were going to use this experiment in my class I would set up the pendulum bars, but then I would provide students with lots of different items they could use to answer the question.  If I wanted to make this experiment relevant to my students’ lives, I would not have them use pendulums.  We would discuss how they think mass and momentum are related.  I would then have them design an experiment based on something in their lives to test their ideas.  Of course, safety would be crucial to these experiments.

Allowing my students to experience the satisfaction of finding their own ways to answer a question is important to me.  For some time, I have been considering ways to improve my students’ problem-solving abilities.  I find that many students become easily frustrated when they have to answer questions that are beyond the knowledge level.  I think giving students a question and giving them the freedom to design a way to answer the question will encourage students to be creative and resourceful.  Hopefully, the feeling of pride that comes from designing their own experiment and finding answers to their questions on their own will encourage them to become more tenacious when faced with a problem.  Another goal for using this type of inquiry is that students will see the science concept at work instead of just reading about it in a textbook.