Every action triggers an equal reaction in the opposite direction. There are many experiments that can use this principle, and it’s my goal to take you beyond your Apologia science curriculum experience, by making science fun and easy for you.
Have you ever kicked a brick wall? Off course you ended up hurting your toe. As strange as it may sound, when you kicked the brick wall, the stationary wall exerted an equal reaction force in the opposite direction, and therefore you felt the pain. Kick harder and it will hurt more- equal reaction force, you see?
This law has been explained by Sir Isaac Newton centuries ago, and came to be known as his Third Law of Motion. This is the same law that is at work when rockets are launched. If you have searched for cool rocketry experiments in the Apologia science curriculum and other homeschool programs, you will be glad that you found me. Let me show you a fun way of using balloons to simulate the launching of rockets.
Single-Stage Balloon Rocket: Take a twenty-foot long nylon fishing line and tie one end to a window or something strong. Pass the free end of the line through a plastic drinking straw and tie the free end to another strong object such as another window or a bed. The fishing line must be stretched and not left hanging loose. Now blow a long balloon and secure the mouth with a clothespin. Tape this balloon to the straw in such a way that the length of the balloon is parallel to the length of the straw.
Now remove the clothespin and observe what happens. When you remove the clothespin, air is pushed out of the deflating balloon with great force in one direction. Therefore an equal force is exerted on the balloon in the opposite direction, and the balloon moves. The same principle is used in launching rockets into the air.
If your Apologia science curriculum experience stopped here, let me take you further. Some rockets that need to go higher use double fuel tanks or double stages. In the next experiment, I will teach you how to make a cool double-stage balloon rocket.
Double-Stage Balloon Rocket: This experiment is similar to the single-stage balloon rocket experiment; only pass the fishing line through two straws instead of one. Make a one-inch ring out of a Styrofoam coffee cup by removing the base of the cup. Now blow a long balloon just enough so that it can fit snugly inside this Styrofoam ring with the rounded head of the balloon extending a little beyond the ring. Secure the mouth of this balloon with a clothespin. Tape this balloon to the straw on the left hand side with the balloon head pointing to the right.
Now inflate and tape a second long balloon lengthwise to the straw on the right hand side. Twist the mouth-end of the balloon to form a one inch tail. Now pass this tail through the Styrofoam ring and under the first balloon. The air pressure of the first balloon will keep the second balloon from getting deflated.
Bring these two connected balloons to the left hand side of the fishing line and remove the clothespin from the first balloon. What happens?
To get great science experiments and activities, visit the free “Homeschool Parent’s Guide to Teaching Science” at the link below.