Kids have a natural desire to experiment.
That’s what makes science class so much fun at those early grades. There are so many simple experiments that are perfect for bringing science to life in the classroom.
This simple sound wave experiment is perfect for introducing the concept of how sound travels.
You may also like these other music STEM activities.
As kids get older it’s important to remember that science shouldn’t be taught only through books. Sure, you can read about how some cereals are higher in iron, but being able to actually extract iron filings from their breakfast cereal brings the lesson to life and helps them remember what they’ve learned.
Before you begin you may want to explain to your child that sound actually travels in waves. This experiment will allow them to test how those sound waves travel.
For another sound wave experiment, try making a paper cup phone.
Sound Wave Experiment
- 2 Pieces of Yarn, 2 Feet Long Each
- Metal Hanger
- Metal Fork or Spoon
Tie the end of each of the 2 pieces of yarn to your fork (or spoon).
Have your child wrap the other ends of the yarn around their pointy fingers several times.
Then have them place their fingers over the opening of their ears. (They shouldn’t stick their fingers into the ear canal, just over the opening.)
Now for the fun part. Have your child tap the fork against the edge of a table or wood chair.
Anyone else in the room will only hear the tap of the silverware against the table. But the child holding the fork with the yarn held by their ears will be delighted to hear a bell-like sound.
Quick Explanation of the Sound Wave Experiment: Tapping the silverware will cause it to vibrate, and those vibrations will make sound waves. The yarn will act as a conductor, and the sound waves will travel up the yarn, instead of just spreading in the surrounding air.
After a few tries with the fork, ask your child what they think will happen if they use a larger metal object, like a metal clothes hanger.
Untie the yarn from the metal fork and tie the two pieces to opposite sides of a metal hanger.
Once again have your child wrap the yarn around their fingers and place their fingers over their ears before hitting the hanger against the table edge.
They may be amazed to hear how different the sound is. The sound will be almost like a gong instead of the higher bell-like sound of the fork.
Take the sound wave experiment farther:
- Let your child explore how the sound changes depending on hard they hit the fork or hanger against the table.
- Try using sewing thread or kite string to see if this will change the results.
- Your child may also want to see how changing the length of the yarn will affect the sound by winding it more around their fingers and shortening its length.
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