Here’s a simple and fun science experiment that can be used to teach children about Action and Reaction. The force from the air moving in one direction propels the balloon in the other direction, much like a rocket.
The supplies needed are everyday household items so there is a good chance you have everything you need to conduct the experiment already on hand.
My kids really enjoyed this simple experiment and had fun doing it over and over with balloons of different shapes and sizes.
Tip: Make the experiment even more interactive and have your kids try to race the balloon across the room!
Watch the Balloon Rocket Science Experiment
- Drink Straw
- Two objects of the same height that you can tie a string to. I used chairs.
How to Create a Balloon Rocket
Step 1 – Position two objects of the same height (I’m using chairs) about 10 feet apart and grab a piece of string.
Step 2 – Tie one end of the string to one of the objects. Make sure it is securely fashioned.
Step 3 – Next, get a straight plastic drinking straw. If the straw is one of the “bendy” straws with the flexible piece, cut off the flexible part so you are left with a straight straw.
Step 4 – Place two pieces of tape on the straw.
Note: Be sure to position the two pieces of tape near the middle of the straw. If you put them near the ends of the straw it will bend when you blow up the balloon and the rocket won’t move as quickly.
Step 5 – Thread the string through the straw.
Step 6 – Tie the loose end of the string to the back of your second object (I’m using another chair) and make sure the string is tight. If the string isn’t tight, move the objects farther apart until it is.
Step 7 – Blow up the balloon and hold the end so the air can’t escape and use the two pieces of tape to secure the balloon to the straw.
Step 8 – Move the straw and balloon to one end of the string. And once you are ready….
Step 9 – Let go of the balloon and watch as it rockets across the string! Then inflate the balloon again and repeat again and again.
How Does the Experiment Work?
The balloon flies across the string because of air and thrust. Thrust can be explained by Newton’s Third Law of Motion. Newton’s third law states that for every action there is an equal but opposite reaction. As the air is released out of the balloon in one direction, the force propels the balloon in the other direction. This equal but opposite force causes the balloon to fly across the string like a rocket!
I hope you enjoyed the experiment. Here are some printable instructions: