My Favorite Heat Transfer Experiment

My students and I both love doing science experiments. Last week we did my favorite experiment for introducing the concept of heat transfer. As I circulated among the groups, leaning in to ask questions and make observations, I was reminded of just why this experiment rocks my socks.

Each group needs:
* a medium sized container for cold water (I use a salad-sized clear plastic lunch tub)
* a small container for warm water (I use a 5oz can of tomato sauce)
* 2 thermometers
* 1 cup of cold water
* 1/2 cup of warm water

When you give the signal, each group should set the warm water container into the cold water container like this:

I watch the clock carefully and every minute I call out "Measure!" The students use a chart to record the temperatures of both containers of water. We do this for 15 minutes. During each minute they need about 30 seconds to actually record so I use the other 30 seconds for tasks like this:
* Talk with your group about what patterns you're noticing.
* With your group make predictions about what the cold/warm water temperature will do next.
* Were your predictions correct?
* With your group come up an explanation for why the temperatures are changing.

At the end of the experiment we do a whole-class debrief, then the students graph their temperatures and write their conclusions about heat transfer on an accompanying index card. Here's one of the graphs:

This experiment is so so simple, but it seems to really stick with us. My students refer to it constantly in later lessons on heat. I think putting the data into a double line graph creates a striking visual that really stays with them.

~ Amanda


UPDATE 8/6/2014 - I've had to turn off comments on this post due to the enormous number of spam comments (nearly 100 per day). It's a popular post for regular folks like us, so I guess that makes it attractive to spammers. Needless to say, if you would like to leave a comment, they are enabled on every other post on the blog so go to it or you can use the Email Me from the button at the top of the page  =)