Sound In a Bottle

Sound

Things You Will Need
• ADULT REQUIRED!!!!
• Bottle similar to old milk bottle
• Stopper to fit the bottle
• Bell
• Piece of wire about one-half the length of the bottle
• Sheet of newspaper
• Match

Do This

1. Attach the bell to one end of the wire and the other end of the wire through the stopper. Be sure the bell can ring without hitting the sides of the bottle when you shake it.
2. Tear a sheet of newspaper into shreds and put some into the bottle.
3. Have an adult light a match and apply it to the paper in the bottle. The burning paper will use up the air and create a partial vacuum.
4. Quickly cover the bottle with the stopper and bell.
5. Wait until the bottle cools then shake the bell and listen. Do you hear anything?
6. Open the stopper to let in air. Replace the stopper and shake the bell again. Do you hear anything?


What Should Have Happened

The burning paper uses up the air and creates a partial vacuum (no air) in the bottle. You should not have been able to hear the bell as well in the partial vacuum, even though you could see the clapper moving in the bell. When you let the air back into the bottle, you should have been able to hear the bell again. The energy of sound travels in waves similar to waves on a pond after a rock has been tossed. These waves cannot travel in a vacuum but have to be carried by a substance such as air, liquid, or solid. The sound waves travel from the vibrating object through this substance to your ear.