STEAM: Balance

Balance is the place on an object where the weight is even on all sides or where there is an equal distribution of weight.  

Do you want to try it? Go ahead and stand on both feet. Close your eyes and feel your weight distribution. Feel all 10 toes and both heels on the floor; maybe shift your body weight side to side.

Try having your feet farther apart, then closer together. What do you notice? Nice job, you’re balancing and experimenting with physics. Physics is a branch of science that studies matter and its motion as well as how it interacts with energy and forces.   

If you don’t feel impressed, that’s understandable. Because when you stand on your own two feet, you have a wide base of support. Let’s try something a little harder—like balancing on one foot.

You may even know without trying that this is harder because you have a smaller base to distribute your weight on. You may feel your weight shifting back and forth as you try to find your center.

What if you hold something heavy, like a book, in one hand? What happens to your balance? Do you have to shift your body weight? You should! Because now there is more weight on one side than on the other, you’ll have to shift your weight to find where it is equal on both sides.  

To challenge your balance even more, try standing on a narrow curb or make a balance board. A balance board is simply a board and a log. You set the log on the ground and place the middle of the board on top. Then you stand on the board and try to balance so that both sides of the board are off the ground. Not as easy as it sounds. 

Now that you have a good understanding of what balance means, let's experiment with the center of gravity. The center of gravity, or the point where the object's mass is concentrated, affects how something finds its balance.  

The Warmup Experiment: This physics experiment can be done with anything you have around the house. Some good suggestions are spoons, pencils, rulers and other long, narrow objects that are not too heavy.  

Place where you think the center of gravity of the object is, on your finger. Then let go. Did it stay put? Or did you have to adjust the object in order for it to balance on your finger?  The point where it stays balanced on your finger is the object’s center of gravity.  

A More Advanced Experiment 

You’ll Need:

• A glass bottle with a lid (or your fingertip works just as well!) 
• Five wooden skewers 
• Four large marshmallows 
• A piece of carrot (you can also use a marshmallow)  

Instructions 

1. Cut a small piece of carrot and place a wooden skewer about 2 inches long into the bottom. Most of the skewer should be outside the carrot.
2. Place the skewer on the top of the bottle, and it will fall over. 
3. Push the pointed end of two skewers into opposite sides of the carrot, and push a marshmallow onto the end of both.
4. Place the carrot on top of the bottle. It should now balance. 
5. Add two extra marshmallow skewers to the carrot and see if it still balances. 
6. Experiment by moving the marshmallows up and down the skewers.

This STEAM activity is adapted from Science Sparks. Visit their website for more information and instructions on how to conduct this experiment, including photos.