Clay Boats
David Brown
Feb. 17, 1997I was interested in your discussion of POE since I had just done a POE in one of my classes tonight. It's a very interesting class with mostly practicing teachers where we do a lot of inquiry activities.
The particular POE was what would happen to a balance with a clay boat and a container of water. Initially the clay boat is out of the water (but resting on the balance). What happens when the clay boat is put in the water? Several had predicted the same weight, and several that the boat in the water would be lighter. When I put the boat in the water the first time, my fingers got in the water and some water stuck to my fingers. As a result the weight was slightly less than the weight with the boat out of the water. Those who had predicted lighter claimed victory, while those who had predicted same weight said it wasn't much lighter so it was about the same. We tried it again a couple of times (more carefully) and got no change both times so the same weight camp claimed ultimate victory.
Then came the task of explaining why - how does the water communicate the boat's weight to the scale....