Have you wondered why balloons make a funny noise when you let them go? Have you also noticed how they move fairly gracefully in circles, then shoot super fast right at the end.
Today we experimented by blowing up a long balloon and letting it loose in the garden.
The kids couldn't believe how high the balloon rose in the sky and how much noise it made!
Why do balloons fly when you let them go?
The neck of a balloon is very tight. Air slips through it slowly, bit by bit. When we looked at it, the neck seemed to flap open and closed, which we think is why it's noisy.
It moves because the balloon is a big piece of elastic. The rubber of the balloon is stretched and wants to return to its normal size. This forces the air out of the balloon. Air leaving the balloon in one direction exerts a force on the balloon in the opposite direction, pushing it forward. This is an example of Newton's Third Law in action.
The balloon's flight speeds up at the end because that is the point at which the elasticity of the balloon has the most inclination to return to its original shape. Have you noticed when you blow up a balloon that it is hard to get it going and then suddenly gets easier? The same applies as it returns to its normal size, but in reverse. So at the very end you have that quick shrinking to its original size which makes it surge forward...
Questions to think about
Is there a way we can make the balloon go in a straight line?
Can you make a balloon make different noises?
Why does the balloon end seem so wet after a few goes?
More science experiments using balloons
Make Balloon Rockets with Preschool Play and Learn.
Create burping balloons with baking soda.
Blow up a balloon with lemon juice to learn about chemical reactions.
Place a skewer through a balloon without bursting it.
Make sure you check out some of our other fun science experiments for kids.
Science concepts
Gravity
Newton's Laws of Motion
Elasticity
Last Updated on March 3, 2025 by Emma Vanstone
JDaniel4's Mom says
I know a little boy that would love this.
ScienceSparks says
It is fab isn't it?
maggy, red ted art says
Brilliant! SO MUCH FUN! I do LOVE Science 🙂
Thank you for sharing on Kids Get Crafty!
Maggy
ScienceSparks says
Thank you Maggy!
Susan says
Why is it after a balloon is deflated so many times that it then can it no longer be inflated? I know a little boy who gets very frustrated by this.
ScienceSparks says
I've never had that happen as ours usually burst before then!
Carrie says
Oh, how neat! I love reading the reasons why things happen. Thank you for sharing at Sharing Saturday!!
ScienceSparks says
So glad you liked it!
Amy says
My boys are so excited to try this experiment. Thanks also for including explanations for some of the questions I know they'll ask. I love the opportunity to make fun and silly play educational!
ScienceSparks says
Let us know how you get on!
Ticia says
Balloons always make great science in my book. Thanks for linking up to Science Sunday.
Trisha @ Inspiration Laboratories says
Great science fun!
Mom to 2 Posh Lil Divas says
What a great experiment/activity - my girls would have so much fun with this. They adore balloons. I featured it on this week's Sunday Showcase - thanks for sharing with us! Can't wait to try it with my girls.