cart Shopping Cart cart(0)

Blow them apart experiment

You will need:

  • 2 balloons
  • 2 x 20 cm  length strings
  • 1 rod or stick
  • 2 identical stacks of books



  1. Stack 2 pillars of books, and place the rod across the two stacks.
  2. Blow the balloons up, tie the balloon ends and attach 1 string to each balloon.
  3. Tie the strings to the rod, so that the balloons hang freely from the rod.
  4. Make sure the balloons are the same height.
  5. Blow between the balloons, can you blow them apart? Try using a hairdryer!
  6. Why can't you do it?

    Bernoulli balloon experiment
    Can you blow these balloons apart?
Be Amazing Book Front Cover; Ben Newsome, teacher & founder of Fizzics Education. Be Amazing -how to teach science the way primary kids love
Be Amazing!
How to teach science, the way primary kids love

Read more about Be Amazing
Want more ideas for teaching science?

Subscribe to the FizzicsEd Podcast!

Listen to FizzicsEd on Apple Podcasts

FizzicsEd podcast available on Stitcher


Why does this work?

The mathematician Bernoulli found that moving air has less pressure than air that is still.
In your experiment a low pressure area was created between the balloons when you tried to blow them apart. The faster the air moved between the balloons, the lower the air pressure in that space.
The high pressure surrounding the balloons pushed the balloons together.

The curved surface of the balloon also makes the air travel faster, causing even lower pressure as the air rushes around the edge of the balloon. Curved surfaces are used to create low pressure areas on plane wings and even F1 race cars! Another simple demonstration of this can be done with a funnel and ping pong balls or making vortex smoke rings. Also, check out this engineering article on F1 aerofoil design!
Other air pressure based science experiments
Join our newsletter for more science teaching thoughts & ideas

Join the Fizzics newsletter

Back to force & movement experiments
  • Learn about forces & motion!
  • Easy & safe to use

    science kits for sale
bell jar science experiment

Flight & Pressure school show

  • Learn how Bernoulli's theorem affects flight
  • Years 3 to 6
read morebook now

>100 Free Science Experiments on this site!

Coloured shadows
  • Experiments to colour your class!
  • Easy & fun
read more
skeleton and student
  • Make fake blood & more!
  • Biology made simple
read more
electricity experiments
  • Circuit science for kids
  • Cheap materials found easily
read more
Sugar and skittles dissolving in water experiment
  • Creative chemical concoctions!
  • Safe and engaging for kids
read more

School Science Visits: 

  • Highly engaging & curriculum-linked
  • Additional Teacher Support Resources
  • Professional visits in-class or via video conference
  • Both Primary School & High School science incursions
Call 1300 856 828 or use this form to discuss or make a show booking for your school!

Love Science?

Signup to our fortnightly email! Learn more

Contact us

1300 856 828

Unit 10/55 Fourth Ave
Blacktown, NSW 2148, Australia
facebook-icon Apple Podcast Icon  twitter-icon
linkedin-icon youtube-icon   pinterest-icon