Make a
balloon rocket
20 minutes
You can move an object by using air that is flowing quickly and forcefully out of an opening. With aircraft or rockets, we use jet engines to do the same thing. You can imitate this at home, using a balloon.
Requirements
Steps
Pass the fishing line through the straw.
Attach each end of the fishing line to a chair. Place the chairs so far apart that the fishing line is pulled tight.
Now inflate the balloon and use a clothes peg to hold the neck of the balloon shut.
Stick the balloon to the straw, using a piece of sticky tape.
How can you make your balloon rocket fly as straight as possible? Cut out cardboard fins, and stick them to the balloon using sticky tape.
Now test your rocket! Pull the balloon to one of the chairs. The balloon’s opening should point to the chair you are starting from. Remove the clothes peg from the neck of the balloon. What happens next?
What did you discover
As soon as you remove the clothes peg from the balloon’s neck, the air is forced out. This air blows backwards. This ‘pushes the balloon away’, making it move forwards.
Can you change your rocket to make it fly even faster? For example, you could change the shape of the balloon, the size of the tail fins, the amount of air in the balloon, the point where you attach the balloon to the straw, or the length of the straw itself.