Can you completely submerge a paper towel under water without it getting wet? The answer is yes, you can! It needs some science trickery, but you’ll be surprised how easy it is!
When the glass is placed in the water, air is trapped inside it. The trapped air prevents water from getting into the glass.
This version of the experiment is vaguely Halloween themed, so I drew a spider on the paper towel.
How to keep a paper towel dry underwater
You’ll need
A large bowl or container
Paper towel/kitchen roll
Pens – optional
Water
Small glass
Instructions
Fill the bowl or container with water and check the glass can be completely submerged inside the bowl.
Cut the paper towel into quarters.
Fold one section of the paper towel and place it in the bottom of the glass. Make sure it stays at the bottom of the cup when you tip it upside down.
Place the glass upside down into the water until it is completely submerged.
Remove the glass. The paper towel should be completely dry!
Try again but this time gently tip the glass as you remove it. What happens?
Why does the paper towel stay dry?
When the cup or glass is placed in the water, water is trying to get into the cup, and air is trying to get out. The two forces ( air and water pressure ) are balanced, so the air stays inside the cup, and water doesn’t move in. This is a great demonstration of air pressure!
Extension tasks
Try using cups of different sizes and shapes. Does it make a difference?
Try one of my other Halloween science experiments.
Science Concepts
Air pressure
Last Updated on October 17, 2024 by Emma Vanstone
