Saturday, May 19, 2012

Singing Tube Science


Being a homeschool teacher, and so naturally, or perhaps by necessity, fond of kitchen chemistry, I have a hard time walking through the grocery store, without making a mental list of potential projects.  There are exploding marshmallows for the microwave, and electrically charged Jell-O in with the baking goods, anthocyanin and bromelain in the produce aisle,  and so on, and so on.

My grocery store finds have not been limited to chemistry either, there are plenty of supplies for biology and physics labs to be found in among the Pop-tarts and laundry soap, as well.  Even the cheapy little toys, placed temptingly at child-eye level, offer scientific promise, such as the sound tubes I encountered in an end aisle display, on one of our latest shopping trips.

Remember those toys - they were big in the '70s. I had one myself, and it was great fun.  Spin them in the air  above your head, and they "sing".  Spin them slow, and the tone is low, spin them faster, and tone rises higher and higher.  That's a science lesson in and of itself...


...but we used ours to demonstrate the Bernoulli effect - that where there is fast moving air, there is low pressure (see this video lesson by Professor Gizmo for a more thorough explanation of the principle).

We secured a plastic bag to one end of the tube with a rubber band, and filled it with air (thanks to Steve Spangler for this idea).


Then, we spun the other, open end - so the air was moving quickly by it, creating an area of low pressure...


...that the higher pressure air, in the bag at the other end, wanted to fill...


 ...leaving us with an empty, fogged up (think cloud experiment), bag.


So, we turned the tube around, and spun the end with the bag on it.  Now, the low pressure was around the bag...


...which was quickly filled...


...by a flow of high pressure air from the stationary, open end, of the tube.


Not too bad for a $1.75 toy. Of course, when we were done experimenting, I removed the hazardous plastic bags, and let the children go off to make beautiful music for the neighbors to enjoy.

It's great to be a homeschooler.

Linked with Science Sunday at Adventures in Mommydom.

Science Sunday

7 comments:

Mama Eagle said...

That looks fun! I'll have to see if I can find one, because my son would find that quite fascinating! He loves doing Science experiments. Recently, he's been watching the Moody Science videos, and has been running around with a pair of tweezers with grains of sugar or sand or such asking for the microscope.

Thanks!

Lily said...

Great idea! Thanks for the explanation!

Phyllis said...

Oh, that is SO cool!!! I love it!

Crafty Cristy said...

Fantastic idea. My kids would love this.

Angela said...

What a great idea, thank you. we are going to work this into our science lessons this month!

Raising a Happy Child said...

You always have the best science idea. I catch myself doing the same in stores...

Ticia said...

And I'm sure the neighbors appreciated it!