What you need:
A Ziploc bag
A big heavy book
A straw
Modeling clay
What to do:
1. Open the zip of the Ziploc bag just a bit and insert one end of the straw into it
2. Using the modelling clay. Seal the bag around the straw. That way the zip is closed and the straw is sealed in. No air can enter or leave the bag except through the straw.
3. Now, place the bag under the book in such a way that the straw inside it should hang off the edge of the table that the bag is resting on
4. Blow hard through the straw.
What happens?
The bag inflates and the book is lifted off the table!
Why?
When you blow air into the bag, you are pushing air in and compressing it. This compressed air pushes against the bag which in turn pushes against the book, lifting it up.
This is also how tyres on our bicycles work. They are filled with compressed air that can take our entire weight!
Picture Credit : Google
