Sound

The other day, Braedi and I were looking through a science experiment book.  She decided that she wanted to make a string telephone.  We made one and I was surprised at how well it worked.  The book gave a simple explanation of how it worked--sound travels better through solid objects.  Speaking into a cup makes the cup vibrate, which makes the string vibrate.  The vibrations travel along the string to the other cup and reproduces the sound.  The process was fascinating to me! 

Rachel DeMille (in the Home-Companion) talks about teaching kids what is "mine".  I wanted to learn more about how sound worked so I pulled some more experiment books off the shelf and looked through the Core Knowledge books and some body books and started teaching the kids about sound.  Braedi had the most fun with it (besides me) and we learned a lot. 

Our first experiment had to do with seeing sound.  We covered a bowl with saran wrap and put a few grains of barley on top then hit a pan close to the bowl.  The sound waves were supposed to make the plastic wrap shake and barely move, but the barely was too heavy.  So, we redid it with sand.  This time it worked!

We tried some experiments with pitch and loudness and location of sound.  We talked about the speed of sound and tried to find a good video of a sonic boom.  We even blew out a candle using sound.

WE talked about our ears and our voice box and how sounds are heard and made.  We tried to make sounds bounce, but weren't successful.  We also made a banger.  Jonathan couldn't believe that I taught the kids how to make these because he remembered them being loud and annoying, but these weren't very loud. 

I love days like these.