1. Sound Lab Monday March 12 th, 2012 What makes sound?

2. What you need to write on your paper: Lab Station #1: Drumming Lab Station #2: Your throat Lab Station #3: Tuning fork Lab Station #4: Rubber band strung Lab Station #5: Buzzer Lab Station #6: Steel yardstick

3. Lab Directions: Every station will have a bright green paper with simple directions on what to do. Make sure everyone takes a turn, then discuss and answer the question you copied from the previous slide

4. Sound Lab 1.) Describe what you hear, feel, and see. 2.) Did the sound ever change and how did you make it change? 3) What are your overall conclusions about the sound at this station? Questions:

5. Sound Lab cont’ Station # 1- Drumming Question 1 Question 2 Question 3

6. Warm up: unscramble the words below Example: vawe = wave *All the words have to do with what we are studying *All the words have to do with what we are studyingdosuncipthtbiiranvoOlssdenurae Happy Monday March 19 th, 2012

7. Warm Up- Respond to the following questions in your lab What happens to sound waves when they reach a wall or other solid, flat object? Explain why, based on the behavior of sound waves, a classroom with a tile floor is louder than a library that is carpeted. Why you see lightning before you hear thunder during storms?

8. Sound Vibration Is a wave that vibrates particles of matter A rapid back and forth movement Sound Wave Notes

9. So then, Why is there not sound in space? Space is a vacuum, which means empty space or very few particles. Sound has to vibrate matter or a medium in order to produce sound. In space there is no ‘air’ or medium for the wave to vibrate, thus no sound can be produced.

10. How do we produce sound? We use our muscles in our body to push air up from your lungs to push air up from your lungs through an narrow passage through through an narrow passage through the vocal cords, which are actually the vocal cords, which are actually folds! folds! The force of air causes them to vibrate That action produces sound waves! From 42sec to 2:58 http://www.youtube.com/watch?v=wYeauSxXSBA&feature=related

11. How does our ears hear sound waves? Vibrations travel though the ear canal Then the sound waves vibrate the eardrum, which moves the 3 bones in the ear called hammer, anvil, and stirrup

12. Continued- How do our ears hear sound waves? The eardrum vibrating causes the three bones in the ear to vibrate, which is detected by the cochlea The cochlea has millions of little hairs inside ear fluid the move with the vibrations, then nerves send messages for the brain to decipher. Do ear cup example http://www.youtube.com/watch?v=tkPj4IG bmQQ&feature=related

13. What affects the speed of sound? Temperature and medium effects the speed of sound.

14. Speed of Sound in Different Mediums If the mediums are all 20 degree C then the following is true... In Air-Gas sound waves travel at 344 m/s In Water-Liquid 1,400 m/s In Steel-Solid 5,000 m/s

15. Speed of Sound in Different Temperatures If you are in the desert and in it 115 degrees F sound will travel faster, then if you are in the arctic and it is -20 degrees F! Why? At higher temperatures particles move faster. So if sound waves push against the already fast moving particles, then it will quickly pass through and vibrate the already fast moving particles. Hall way example

16. Frequency A given number of waves in specific amount of time, which determines the pitch. The pitch is a characteristic of high and low sounds. Frequency is measured in hertz. (hz)

17. The Doppler Effect The Doppler Effect is a change in the perceived pitch when the source of the noise is moving. So to Further Explain: All waves, light and sound, travel out from the source, but when the source is moving the waves get bunched closed together making a higher frequency/pitch and the waves trailing behind become spread out making a lower pitch/frequency. http://www.youtube.com/watch?v=Kg9F5pN5tlI

18. Amplitude Amplitude determines intensity, which is just how loud sound is. Intensity or amplitude of sound is measured in decibels (dB).

19. Decibels (dB) Examples: 10 dB Leaves Rustling 30 dB Whisper 60 dB Dog Barking 90 dB Motorcycle 140 dB Firecrackers

20. 1.What is sound? 2.How many bones are in the ear? 3.What part of the ear has millions of hairs and fluid in it? 4.What are the two main parts of the body that help to produce sound? 5.Is it easier for sound waves to pass through a solid or a liquid? Why? 6.Is it easier for sound waves to pass through a hot gas or a cool gas? Why? 7.Frequency determines the __________ of the sound and is measured in ______________. 8.Explain the Doppler Effect. 9.What is an example of the Doppler effect? Pop Quiz : D *Don’t Worry you can use your notes.

21. Review Practice Questions Question 1- Which do you hear 1 st.... 1- Your postman saying “Hi” from 20ft away 2- A car crash 500 meters away 3- An air plane taking off 10,000 meters away

22. Review Practice Questions Question 2- Why can you see something happen then hear it? For example a tree far off falls then a second later you hear it. 1-The sound travels in many directions at once 2-Sound is a wave 3-Sound faster than light 4-That is just how much time the sound takes to reach the listener

23. Review Practice Questions Question 3- How does cupping your hand to your ear help you hear? 1-Sound waves move through you hand 2-The hand reflects the more sound waves into the ear 3- More sound waves are refracted into the ear 4-There is more air for the sound waves to more through

24. Review Practice Questions Question 4- What effects the intensity of the sound most? Pick 2 1-Temprature of medium 2-Length of medium 3- Material of medium 4-Color of medium 5-Transparcy of the medium

25. Review Practice Questions Question 5- Fill in the blanks: ________________ determines the pitch and ____________________ determines the volume/loudness. 1-Wavelength:Intensity2-Frequency:Wavelength3-Intensity:Frequency 4-Frequency: Intensity