Exploring Heat Transfer

This week's inquiry experiment was fairly simple on paper; fill four identical mugs, pour some hot water into them and cover each with a different insulator found around the house. Leave the covered mugs on the counter for 30 minutes and then measure the temperature change with the thermometer from our science kits.

There was no stipulation as to how hot the water needed to be so I put each mug in the microwave for 2 minutes each, then covered them and left them out. Half an hour later I attempted to measure the temperature and discovered that my little thermometer could only reach 50 degrees Celsius. Sooo....I had to toss that experiment. Unmeasurable= Invalid.

Next, there was a lively debate between my fiance, my fiance's son who is an AP student in science and myself. We went back and forth on whether I should microwave the water or use hot tap water, if I should do all the mugs at once or one at a time and what insulators I should use. That's typical for my house, being surrounded by smart people is lively if not informative.


I decided to do it my way. I usually do. I heated tap water to its hottest, measured one cup of water, put it in the mugs and topped them. I came back half an hour later and checked the temperature. Strange, how on earth could the plastic baggie be the best insulator? Something had to be wrong, I had also used a 1" piece of Styrofoam, a piece of foil and a wash cloth as my insulators. Surely the washcloth or the baggie had to be poor insulators but no, it didn't work that way at all.


So I sighed, and did the experiment once more. It sounded so simple on paper!


This time when I measured the results, the water for  the Styrofoam, the baggie and the wash cloth all measured in at 36 degrees Celsius. What was up with the Styrofoam? It ended up that the foil won out with a temperature of 37 degrees Celsius.


I decided to leave my experiment at that. Maybe foil as an insulator was something I could look into later on in my free time. It also occurred to me as I was pondering the results that this experiment had no control and to get truly valid results, I would have included a control.


My conclusion: I wouldn't have my students do an experiment like this having tried it on my own with three widely different results. If I was instructed to have my students do it despite my objections, I would give more specifics; give a starting temperature for the water, and to make sure they used a control.


And now for a question from my professor:
What, specifically, would you like students to learn from this experiment?

To answer that question, I pulled up the Sunshine State Standards for Fifth Grade-

The Nature of Science
Standard 1:
The student uses the scientific processes and habits of
mind to solve problems. (SC.H.1.2)

Standard 2:
The student understands that most natural events occur
in comprehensible, consistent patterns. (SC.H.2.2)

6. knows ways that heat can move from one object
to another.

Did you achieve this goal when you engaged in the experiment?

To be honest, I did not. The experiment shows that insulators work to contain some heat, but does not show where the heat went nor how it escaped the coffee mug. 

LOL - Physics

How do different surfaces affect the momentum of marbles?

My assignment for this week was to select a topic and create a guided inquiry experiment to suit the topic. I decided that this would be fairly simple; chose a marble, get a ramp, chose a height for the ramp and find a measuring tape. I next decided to try the marble roll on carpet, tile floor, concrete and sand. (Living in Florida we have Lots of sand). 

First trial, I sent the marble down the ramp. Our cat was watching in rapt attention and pounced on the ball as soon as it hit the carpet. As we all know this introduced a new variable (add cat?) and we can only have one variable in our experiment. So I put cat in the bathroom and finished up with the carpet trial.

Second trial, I sent the marble down the ramp to see how it did on my tile floor. It hit my front door and bounced back. I tried twice just to make sure.  I had visions of my students running all over the classroom, leaping over desks and hollering about catching marbles so I decided to skip the trial on tile. 

Third trial I went outside with my little ramp, box, measuring tape and marble. I’m certain by now that my neighbors wonder about me, with my having checked out 14 little solar cars previously on the sidewalk in front of my house (I had to make sure they were all working, of course). I’ve noticed that my neighbors tend to veer wide of the sidewalk when I’m out doing my experiments. 

Fourth trial was on the sand across the street, now my neighbors were avoiding me completely.

Now my trials were done and I went in to write up my paper. Here are some questions from my professor with replies:

How could you make this experiment more fun, interesting, or engaging for your students? Actually any time they get to play with marbles is good with them. Fifth grade students believe they are the ‘big kids’ but they still like to play. One thing I would do is to put them in groups of three, with a leader, equipment manager and a secretary. They work better with assigned roles rather than every man for himself.

How might you design this experiment so that it is relevant to students’ lives? I would do this with a class discussion about friction and momentum on highways, why it is important to have some friction and what would happen if there were very little. How would it affect the momentum of cars? 

What specifically would you like students to learn from this experiment? I want them to learn that different surfaces affect the momentum of things that come in contact with them. Some surfaces hasten momentum and others slow it down. Essentially.  Did you achieve this goal? I don’t know as I haven’t done this with my students. I imagine that they would understand it, especially if I keep the focus on the topic and give all students a way to connect to the experiment.