How Do You Sink Wood?

Our investigation on Thursday was about how we could sink wood.  Most of our scientists expected that the samples of pine and plywood would easily sink to the bottom of the basins of water.  Only one problem…they didn't!  We needed to investigate and discover how we could make them sink.  Since Ms. Kieltyka was here, we were able to split up into two groups of scientists.  We examined the samples of pine and plywood and set off to work.

Since the wood samples did not sink, we had to figure out a way to make it happen.  One of the scientists suggested that they needed to "be heavy".  Great idea…but how could we do that?  We used paperclips for weight.  We added five paperclips to each sample of wood and attached them with a rubber band.  Surely this would make them sink!

   

   

But they did not sink.  They flipped over so that the paperclips were on the bottom, but no sinking.  So now we added five more paperclips to each wood sample.

   

   

   

   

Then things got interesting…the plywood sample actually sank while the pine sample was still floating!

We wondered about why the plywood sank but the pine did not.  Derrick suggested that it was because of the glue that is used to make plywood.  He was correct!  Now we had to make the pine sample sink. You guessed it…more paperclips!

   

The group working with Mrs. Kurt needed 20 paperclips to sink the pine.  The group working with Ms. Kieltyka needed 21 paperclips to make it sink.  As usual, we recorded our observations in our science notebooks and reported out to the group when we were done.