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How can a blown-up balloon help you hear? In this week’s Saturday Science, from Science Kids, discover how sound conductors turn small sounds into BIG noise!
Materials
- Balloon
Process
- Blow up the balloon.
- Hold the balloon close to your ear.
- Lightly tap on the other side of the balloon and listen closely. What do you hear?
Summary
Were your light taps quiet or loud? They were probably louder than you expected! You can thank the air molecules inside the balloon for that.
When you blow up a balloon, you force the molecules close together and create a better conductor of sound waves than the air outside of the balloon. This is similar to when a house guest knocks on the door and you’re already close by. Your guest’s knock sounds much louder than when you are far away. In solids, like a front door, sound molecules are really packed together, which makes them a great conductor of sound!
And what about liquids—are they good conductors of sound too? Yes! Try this experiment with a glass of water instead of the balloon and see for yourself.
Want more Saturday Science? See all of our at-home activities on the blog or Pinterest.
