Experiment
Balloon rocket
Can you make a rocket out of a balloon?
Curriculum objectives - Science:
- conversation about what energy is, and explore different energy chains
You need:
- A balloon (preferably a long one, but round is also fine)
- A long string (several meters)
- A straw cut in half
- Tape
- A clothespin
This is what you do:
Thread the pieces of straw onto the string and tighten it up so that you have at least 3-4 meters of string.Roll
a piece of tape so that it has glue on the outside and stick it on the pieces of straw.
Inflate the balloon and pinch the opening again with the pinch.
Tape the balloon to the straw pieces.
Pull the balloon to one end of the string so that the opening of the balloon is closest to the end.
Remove the clothespin and watch the rocket pick up speed!
Explore and observe:
- Use a different balloon shape. Does the shape of the balloon affect how far (or how fast) the rocket travels?
- Change the length of the straw. Does the length of straw affect how far (or fast) the rocket moves?
- Try a different type of hoisting, eg fishing line, nylon string, cotton string etc. Does the hoisting affect how far (or how fast) the rocket travels?
- Change the angle of the hoisting. Does it affect how far (or fast) the rocket moves?
What is going on?
So how does it work? It's all about air and thrust. As the air rushes out of the balloon, it creates a forward motion called THRUST. Thrust is a pushing force created by energy. In the balloon experiment, our thrust comes from the energy of the balloon forcing the air out. Different sizes and shapes of the balloon will create more or less pressure.
In a real rocket, thrust is created by burning rocket fuel as it blasts from the rocket engine - when the engines blast down, the rocket goes up!
