Supplies Needed for Center of Gravity Butterfly Experiment

Series Summary

An object or physical mass is said to exhibit a center of gravity or center of mass when, upon identifying and properly specifying such a point, the mass behaves as if it is concentrated. In physics, the center of mass is the combination of system particles that determine the object's behavior, and for rigid objects, will appear at a point on itself. For loose or free space objects such as bullets fired from a gun, the center of gravity will be a point in space. In a so-called uniform gravitational field the center of gravity is also called the center of mass. This center might not be physical center of an object, though, and depends upon the division of weight, counterweight and physical arrangement of parts.

In this free instructional video clip series, our expert will demonstrate a children's science experiment that explains and properly displays the variations on the center of gravity for a particular mass. In the series, the popular science fair and science class demonstration known as the “Balancing Butterfly” will be explained. Teach your children a very simple lesson in physics or help them duplicate the project for school with this easy to follow collection of videos outlining the project from supplies to counterweight balance.

Video Transcript

" Hi I'm Scott Thompson for expertvillage.com, and today I'm going to demonstrate a center of gravity activity using balancing butterflies. What you will need for this activity first of all is a butterfly shape. These are templates that use patterns that the students use to trace onto their own card stock. So just a little bit heavier then paper. You can get these either online. If you just do a search for butterflies, you would get a larger shape that you can end up tracing to your own templates. Or I have seen them in kids' coloring books. Wherever you think that you can find them you probably will. They don't have to be exactly this shape, but about this size seems to work pretty well. The secret of the balancing butterfly is the counterweights that you attach on the other side of their wings. This can either be pennies, or washers, or even buttons. I have seen a variety of things that you can use, as long as they are exactly the same on each side of the wing; that is where the balance comes in. But that is part of the lesson; if students struggle with it, that is because they maybe don't have exactly the same weight object on both wings. So we got templates you will need. Weights. You would also need scissors to cut a toothpick to the right shape. The toothpick actually gives the butterfly's body a little bit of stiffness; that gets glued on to the other side. Glue stick—the glue stick is used to attach the weight to the wings. I like glue sticks instead of hot glue for the weights, because it allows you a little bit of time and moves the weights around to get it balanced just right, but that, it doesn't set up very quickly. But for the toothpick, hot glue comes in handy. Use a low temp glue that is safer, and probably safety glasses are a good idea."