Things You Will Need
- Several clean, glass bottles that are all the same size and shape
- Spoon or small stick
- Collect several clean, glass bottles that are all the same size and shape.
- Put the bottles in a line.
- Fill one bottle with water almost to the top. Leave some air above the water.
- Put a little less water in the next bottle and so on down the line. The last bottle should have just a small amount of water in the bottom.
- Blow across the top of each bottle. Which bottle makes the highest note? Which bottle makes the lowest note?
- Using the spoon or small stick, gently tap each bottle. What happens to the notes?
What Should Have Happened
You should have heard musical notes when blowing into the bottles. This happens because you are making the air inside the bottle shake or vibrate. The different notes are made because there are different amounts of air inside each bottle. When you blow across a bottle with a small amount of air inside, the air vibrates quickly and makes a high note. With more air in the bottle, the air vibrates slowly and the note is lower.
When you tap the bottles, you make the water vibrate instead of the air. So the musical notes will be the opposite of those you produced with air. The bottles with a small amount of water give out high notes and the bottles with a lot of water give out low notes. Musical instruments such as recorders, organs, or trumpets work in a similar way. The player blows into the end of a pipe and this makes the air vibrate and give out musical sounds.
Webdate: June 11, 2002
Updated: July 2004
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