VIDEOS
9. Get two bottles and fill one half way with water. Blow over each. Note that the sounds are different. A) What is the difference? B) Why? (10)
A. The amount of air in the bottles
B. When you blow into the bottle, you make the air vibrate. The bottle with the less amount of water in it will produce a lower pitch sound compared to the bottle filled with more water. Having more water in the bottle decreases the amount of space for air to vibrate and for the pressure to build up, creating a higher pitch sound.
10. Get an oven rack and tie two strings to it. Make a loop in each string and put your fingers through the loop. Put your fingers in your ears and LET THE RACK HANG FREE. Have someone bang on the rack with different objects and compare the sound with and without your fingers in your ears. A) Why is the sound different? B) How does this relate to why your voice sounds different to you than it does to other people. (10)
A. The sound is different because we are hearing the vibrations through our skull as opposed to the sound waves traveling and hitting our ear drums.
B. When you talk, you hear your voice through the vibrations in your skull from your vocal chords. Other people hear your voice through sound waves that travel to their ears.
*dad insisted on wearing that