Thursday Teaching {Balancing Bird}

Project: Balancing Bird

Concept: Center of Gravity

Wikipedia says: "The center of mass is often called the center of gravity because any uniform gravitational field g acts on a system as if the mass M of the system were concentrated at the center of mass R."

I say for your kiddos: It's 'the average location of the weight of the object'.

Explanation for the kids:

Take a ruler or a pencil. You can find the center of gravity of these objects by balancing them on your finger. I'm sure you did this in Mr. Wengel's English class trying to stay awake, but it's probably totally new to your kids!

Well, this is relatively easy because a ruler and a pencil more or less have a uniform shape all the way around. The bird we are about to do doesn't have a uniform shape, so we'll have to make some adjustments.

Finding the balance point of a paper bird is not impossible using a steady hand and a pen, but your kids will have more fun flying around the house with their bird on their finger.

You can see that the center of gravity is not very close to the beak. How could we move the center of gravity? Well, we need to make the beak the place where there is equal weight on both sides of the bird. So, we have lots of paper on the back half of the bird, but very little paper on the front half.  We need to add something more to the front half to make both sides even. We'll add some weights. Make sense?

Use paper that is thicker than computer paper: cardstock, construction paper, cardboard, etc. In general, the thicker the better!

Draw your bird. This is a general shape, but have fun with it. The only requirement is that the wings extend past the bird's head.

Cut and color and color some more. Bow inspired by the adorable little girl sitting next to me.

Add pennies on wingtips (with tape - Gluing is illegal :))  and balance! It may take a couple tries to get it just right.

Switch pennies to the inside for maximum coolness!

For the older kids: Experiment with other animals or shapes. I've seen parrots and monkeys, so no holding back. Remember you're looking for even weight distribution. Ask if they can find a way to disguise the pennies on the outside - turn them into eggs, for example. See if you could get two birds to balance off each other. The possibilities are endless!