In the photo, kindergarten students are using a balloon rocket to learn about forces.
How to make a balloon rocket:
1. In the photo shown, a string is stretched between two chairs. Decide where you will attach the ends of the guiding string for your balloon rocket. Measure and cut a string long enough to span the distance and be secured.
2. Cut a 4 inch piece from a drinking straw.
3. Thread the string through the straw piece, then secure the two ends of the straw to form the guide strings for balloon rocket.
4. Slightly inflate a balloon, but don’t tie the end. Instead pinch the end of the balloon to keep the air from escaping. While holding the end of the balloon closed, ask a helper to tape the balloon to the straw as shown in the diagram.
5. Pull the straw with the attached balloon to one end of the string.
6. Release the balloon and observe how far as well as how fast the balloon moves.
How to Design a Balloon Rocket Science Project
A science project has two variables. Variables are things that can change.
The two variables in a science project are called:
independent variable–Something that you choose to change in order to determine if/how it affects the dependent variable.
For example: You might change the amount of air in the balloon to determine if the amount of air affects the speed of the balloon rocket.
- Amount of air = Independent Variable
- Speed of Balloon Rocket= Dependent Variable
Your Project Question : What affect does the amount of air in the balloon have on the speed of the Balloon Rocket?
Your Hypothesis: This is your prediction as to how the amount of air affects the balloon rocket’s speed. You need to give a reason for your prediction.
If you do not have the instruments to measure the speed of the balloon rocket, you could set up two or more rocket guide strings and with the help of assistants, blow up testing balloons with different volumes of air at release the balloons at the same time. Video tape the “race” between the balloons so that you have documentation of the results. Repeat the test four or more times to verify the results.
Results/Data- Data Charts can be used to confirm your results. Use the results to prepare graphs for displaying your results.
More About Balloon Rockets
For more information about Balloon Rockets— including why the balloon moves forward when the air is expelled in the opposite direction see, Balloon Rocket Projects.