Sent in by:
Stephen of Germantown, TN
Sound wave science, in stereo!
- metal coat hanger
- bowl of water
- metal spoon
- Tie the ends of a piece of string to each corner of a metal coat hanger.
- Then loop one end of the string around one index finger and the other end around the other index finger.
- Put your fingers in your ears and bang the hanger against a table.
- The sound waves from the vibrating hanger travel through the string and into your ear.
- Do the same thing with a metal spoon.
Now try experimenting. Different materials vibrate differently. See if you can hear a difference in the way a muffin tin sounds. What do you think will happen? Make a prediction. Then change one thing-that's the variable-and test it out. Be sure to tell us what you thought was going to happen and what actually did happen. When you're done, send your reports to our special feedback area. Every week we'll post new results from ZOOMers' Stereo Hanger experiments.
Trini, age 10 of Miami wrote:
When I taped the hanger with the string, I heard a tiny beat. Once I put my fingers in my ears I heard a LOUD beat compared to the other. After I tried a spoon and it made a high sound when I had my fingers in my ears. This was a cool experitment!
Zachary, age 9 of Miami, FL wrote:
When I hit the metal coat hanger, it sounded like a deep bass drum hit. When I hit the spoon it sounded like a triangle. This experament was great and I would prefer it to anyone.
Jenna, age 11 of Miami, FL wrote:
When I banged the hanger against the table it had a lower tone and the vibrations felt the same when I used the spoon.
Thajia, age 11 of Miami, FL wrote:
it was awesome because when I hit different things on it it, it made a sound like big ben when it hits 12:00
Huy, age 10 of Miami, FL wrote:
When you bang it, it feels like you're vibrating as well.
Jason, age 10 of Miami, FL wrote:
when I banged the metal hanger on the table with out putting my fingers in my ear I heard a low vibrating sound and when I put my fingers in my ear the noise was a lot louder
Mintra, age 10 of Miami, FL wrote:
In the Stereo Hanger experiment, I learned that vibrations can travel through objects. When I hit the metal hanger on the table, without my fingers in my ears, I heard a high clacking sound. When my fingers were in my ears, I felt vibrations and heard a low drumming sound. When I hit it on the wall, with and without my fingrtd in my ears, it resembled to my results on the table. When I hit it on a metal bottle, there was a high sound with lots of vibrations. When I put my fingers in my ears, there was a low sound. In this experiment, I've noticed that when I cover my ears, sounds that things make when they bidrate have a lower sound than when your ears aren't covered.
James, age 10 of Miami, FL wrote:
During my experiment, I heard a loud boom when I hit my hanger against the table. It was a fun experiment
Andres, age 11 of Miami, FL wrote:
First, when I knocked the hanger against the wall there was a medium-pitched noise. Then when I knocked against a wall, there was a low sound, like a church bell. However, when I knocked it against a bolw of water, it was very high-pitched
Tommy, age 10 of Miami, FL wrote:
When I banged the hanger against a wooden table and a cardboard box it made a low rumbling sound. When I banged the hanger against the floor, refrigerator, glass table, concrete, and the wall it made a "Ping!!!" sound. When I banged the spoon against a wooden table it made a bell tower sound. When I banged a metal muffin tin against a wooden table it made a low "Ping!!!" sound. When I banged a metal wrench against a wooden table it made a wind chime sound. When I banged a metal key against a wooden table it made a high pitched sound. This experiment was awesome!!! In conclusion, the heavier the metal thing is, the higher pitched the sound is.
Krystal, age 11 of Miami, FL wrote:
It was awesome! I belive that the best part of the experiment was when I tapped it against the glass. The loud pitch sounded like tires screecing loudly against pavement trying to aviod an accident.
Mac, age 10 of Miami, FL wrote:
When I used the table, there was a resonant sound, which was like a bell but lower. When I used the spoon, there was a shrill, piercing sound. Then I used a crystal bowl, which had a deep and low sound. Then I used a mirror which had a high and clattering sound. After that I used two cartons of milk. One was full and another was almost empty. Their sounds were alike, except the full one was deeper and had more of an echo. This experiment was really fun to do.
Gabriel (The Math Genius), age 10 of Miami, FL wrote:
I tried the experiment with the metal coat hanger and it had a low pitch sound. Next, I tried it with the metal spoon and it had a higher pitch than the coat hanger. Then I tried it with a metal tool and it had an even higher pitch sound! Finally, I tried it with a plastic marker and it made no sound.
Noah, age 10 of Miami, FL wrote:
When I tapped the metal hanger on the table with the string only it made a tiny beat, but when I did that with my fingers in my ear, it made a drum beat. When I tapped the metal spoon on the table, it made a bell like sound. Finally when I tapped a metal ruler on the table, it made a sounded similiar to a garbage can falling. This experiment was awesome.
Julian, age 10 of Miami, FL wrote:
I heard a very gentle string instrument playing in my ear when I did it with the hanger. When I tried it with a spoon it felt as if I were listening to a high- pitched church bell from far away. I can apply this experiment with my life because when I go buy a string instrument, the strings make different variety of sounds depending if the wood is heavy or light (low or high pitched). Also I found out that in an instrument the strings are pushed against the wood causing it to make sound energy.
Lauren, age 10 of Miami, FL wrote:
When I hit the table, I heard a higher sound than when I put my fingers in my ears. I think this happened because sound waves travel better through the string (solid) than through the air(gas).
Darius, age 10 of Miami, FL wrote:
When I banged the hanger against the table, with my fingers in my ears I, heard like a loud bang, sort of like a drum. Also I felt a lot of vibrations, like a phone stuck in my ear.
Camron, age 10 of Miami, FL wrote:
When I did this experiment, it was very hard to put it togehther. But, when I finally got it together (with the help of my father), the hanger sounded like a church bell or bell tower! When I took the hanger from my ears, it made a low humming sound! Then, I tried the spoon. The spoon sounded like a little hummingbird! But, when I took it down from my ear, it was just a "Ding, ding, ding!" The other things I tried made little to no noise at all!
Jahel, age 10 of Miami-Dade, FL wrote:
with the hanger it made a high pitch sound But with the spoon it made a low sound. I personally think that its agreat little project to teach you about high, low pitch and sound waves for everyone
Melissa, age 10 of Miami, FL wrote:
I heard LOTS of different vibrations! It was AWESOME!!!
Trini, age 10 of Miami, FL wrote:
When I banged it, I heard a LOUD sound in my ear. When I took my fingers off my ears I heard a very little sound compared to when I had my fingers on my ears.
Johnny, age 10 of Miami, FL wrote:
I heard a buzzing sound like a zipper
Ayushi, age 10 of Miami, FL wrote:
Before I did the experiment I looked at the materials. I wondered what a bowl of water had to do with this. When I conducted the experiment there was no use of the bowl of water. But the experiment was very cool. I never knew tht sound waves could travel in string. I heard different drmming sounds. Low or high. I would improve this experiment by explaining what each material does and what it has to do in the experiment. But it was very interesting.
Chase, age 10 of Miami, FL wrote:
When I did it with the hanger it sounded like a metallic sound and I felt a vibration. But when I did it with the spoon there was a stronger vibration.
Giani, age 10 of Miami, FL wrote:
When I hit the metal coat hanger against anything there was a vibration going through the coat hanger and through the string, and since the the ends of the strings were wrapped around my finger and my finger was plugged into my ears I felt and herd the vibration. Depending on the material the table was made of such as wood, metal, concrete, glass,... the vibration either made a deep clonk or a high clink and maybe some were in that experiment I could have heard a cloink.
Logan, age 10 of Miami, FL wrote:
For the coat hanger it made a drumming noise that vibrated from the rope to my ears. The spoon made a light tapping noise. It was an awesome experiment!!!
Vincent, age 13 of Melbourne, FL wrote:
When the hanger tapped against the table with the string, I heard a small beat. When I put my fingers in my ears, I heard a loud drum sound. When I used sewing thread, I heard a low metallic sound. When I put my fingers in my ears, I heard a high metallic sound. When I hung scissors from the hanger, I heard a deeper metallic sound.
Tre, age 14 of Jefferson City, MO wrote:
This experiment was awesome! It worked on any surface. The table, chair, wall, other hangers, even myself!
Mitchell, age 10 of Jefferson City, MO wrote:
The hanger made a really loud sound. It was cool.