Can't Roll Away Can

My oldest son, and I, were googling around a bit yesterday, searching for ideas for homemade toys to make for Christmas. We didn't come up with any must make present ideas, but we did run into a try-this-at-home science toy video, with instructions for making a can, that rolls back to you, when you roll it away. That worked for us, since there's a Sunday Science link up over at Adventures in Mommydom, we were hoping to participate in today.

So this evening, after a nice long Sunday afternoon nap, we gathered our supplies, and set to work.

To make our Can't Roll Away Can, we used:

• a coffee can, with a small hole poked in the middle of the the bottom, and the lid.


• two rubber bands (only one is pictured, but we added a second one, as we went to work), our first rubber band, was thick, and shorter than the can. But, when stretched out, was just a tiny bit longer than the can.




• a wooden skewer


• a number of metal washers


• and two toothpicks
  

We used the second rubber band to tie the washers to the the middle of the first rubber band.

Then, centering the washers in the can, we used the wooden skewer to push the ends of the rubber band out through the holes in the bottom of the can, and the lid.

We secured the rubber band in place, with the tooth picks.

Finally, we rolled the can. As, it rolls, the washers inside the can, cause the rubber band to twist, storing up energy. When the can stops, the rubber band untwists, releasing the energy, causing the can to roll back. Below is a very basic video demonstration, of the can rolling away, and back again (it's my first attempt at adding a video clip to the blog).

Click here, to go to the Howcast video where we found these instructions, as well as another set of instructions for making a spool tractor, and an interesting looking paper airplane. It gives a little better explanation of the science behind the can.

Then, you might want to click over to Adventures in Mommydom, for more fun science activities.

It's great to be a homeschooler.