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Feel and see sound waves at work!
Try this! Put your hand on your throat and start singing. Can you feel your vocal cords vibrating (moving back and forth)?

All sound is created by vibrations. Those vibrations, called sound waves, move through the air. When they reach your ear, they bang up against your eardrum and make your ear drum vibrate. Your eardrum sends messages to your brain that your brain understands as sound. Sound waves may be invisible, but they make a big impact. In fact, you can see their effects.

Use sound waves to blow out a candle.

What You’ll Need:

• Round oatmeal box
• Scissors
• Candle in a holder
• Match
• An adult helper

image of sound waves

 

Step 1. Set up your experiment.

Here’s how:

  • Cut a round hole in the lid of the box. The hole should be about the size of a penny. Put the lid back on the box, and place the box on its side.
  • Ask an adult to light the candle.
  • Place the candle in its holder about four inches from the hole in the box. Be sure to keep the candle at a safe distance from the box.

Step 2. Watch sound waves at work!

  • Lightly tap the bottom of the box. It will sound like a drum.
  • Watch the flame. Did you see it flicker or go out?

When you tapped the box, you sent sound waves moving through the box and out the hole. When the sound waves hit the flame, they made it flicker or go out!

TRY A RELATED EXPERIMENT! -- --- >

Mother and child doing activity

 

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