Making Sound at Salt to See Vibration

First Name: Anna
Age: 7
Experiment Title: Making Sound at Salt to See Vibration
What was the purpose of your experiment? Provide a brief description of what you were hoping to learn, discover, or study.: We were trying to see how sound waves work by putting salt on top of plastic wrap on top of a bowl. We put the salt there so that if we used something to make a sound that maybe it would cause the plastic wrap to vibrate which would cause the salt to jump up and down.
What was your hypothesis?: My hypothesis was that the sound made by hitting paper would not make the salt move. I thought that a hitting a plastic cup would work. I though that a toy gun’s whirring noise would not work. I also thought that the blow up guitar’s squeaking would not work. I thought the paddle ball would work. And I thought a scream would work.
What materials did you use in your experiment? List them all.: I used:1. a bowl
2. plastic wrap
3. salt
4. a measuring cup
5. a spoon
6. paper
7. a plastic cup
8. a toy gun
9. a blow up guitar
10. a paddle ball
11. my voice
What procedure was followed? Provide a brief description of the steps you followed during your experiment.: First we took the bowl out and we wrapped the plastic wrap around the bowl. We made sure the top of the bowl was covered in plastic wrap tightly. Then we sprinkled some salt onto the plastic wrap. Then we tested out the different things by using them to make noise. We stood close by the salt.
What were the results of your experiment?: The results were: the paper did not work, the plastic cup did work, the gun did not work, the blow up guitar did not work, the paddle ball did not work, and the scream worked the best.
What is your conclusion after conducting the experiment? Was your hypothesis correct or incorrect? What did you learn?: My hypothesis was half right, half wrong. I don’t know why some of the sounds did work and some did not. But I think maybe it is because they were a different type of sound. Some were louder and some may have been more muffled (like in the gun, the sound may not have come out of the bullet hole enough). Also, some waves may have been longitudinal waves and others transverse waves.