Sound experiments

Today we read a book called Amazing Science Amazing Sound. It discusses how sound travels through different mediums. We conducted several experiments to go with our study.

1. Identified sounds going on around us
2. Cup hand around ears; sound is magnified
3. Discussed vibrations. Clapped loudly & quietly. Loud sounds are made by large vibrations, whereas quieter sounds are made by small vibrations.
4. Felt the voice box while making high and low pitches
5. Sound waves travel through water. We created our own waves in a bowl of water.
6. Bounced a ball off the wall to see how an echo works. Our voice bounces back off the wall just like a ball. (When you shout in a cave, your voice bounces off the walls, and you hear an echo)
7. My favorite experiment was the sound in action experiment. You get a coffee tin can, stretch plastic wrap tightly over the top. Sprinkle coffee grounds lightly on top of the plastic wrap. As you bang another coffee can with a spoon (the open tin can pointing toward the coffee grains), the coffee grains jump. This proves that sound travels in waves because nothing but the sound is causing those grains to jump.
8. Discussed how a shorter string on a musical instrument (we used Justin's guitar) produces a higher pitch. A longer string produces a lower pitch.
9. We also watched 4 Cello performances on YouTube. We watched and discussed how the Cello players produced higher and lower pitches with their instruments as we watched their hands move on the neck of the Cello.

Here is another interesting experiment with high pitched sounds(using sand) that we watched: