# Photo Album - PowerPoint PPT Presentation

Photo Album

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Photo Album

## Photo Album

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##### Presentation Transcript

1. Photo Album by Robert MacKay

2. Sound waves are longitudinal waves • http://faraday.physics.utoronto.ca/IYearLab/Intros/StandingWaves/Flash/tunefork.html

3. Audible range 20 – 20,000 Hzdecreases with age and damage

4. Speed of sound in Air • Depends of the air temperature. Higher air temperture the higher the speed. • Depends of the molecular mass of air. Faster in helium, slower in air, and slower yet in Xenon.

5. During a lightning storm the thunder is heard 6 seconds after the flash. How far away was the lightning strike?

6. During a lightning storm the thunder is heard 6 seconds after the flash. How far away was the lightning strike? 2 km

7. Speed of sound in Air • Depends of the air temperature. Higher air temperture the higher the speed. • Depends of the molecular mass of air. Faster in helium, slower in air, and slower yet in Xenon.

8. During a lightning storm the thunder is heard 10 seconds after the flash. How far away was the lightning strike?

9. During a lightning storm the thunder is heard 10 seconds after the flash. How far away was the lightning strike? 2 miles

10. Speed of sound in solids • Depends of the elasticity of solid. The stiffer the solid the higher the speed. • Depends of the solid density. The lower a solid’s density the higher the speed.

11. Beats • The beat frequency is the difference between two frequencies.

12. Beats are used in tuning • when tuning a guitar a beat frequency of 3 Hz is heard when comparing the sound from the guitar to 256 Hz tuning fork. • What is the guitar string’s frequency?

13. Beats are used in tuning • when tuning a guitar a beat frequency of 3 Hz is heard when comparing the sound from the guitar to 256 Hz tuning fork. • What is the guitar string’s frequency? 253 or 259 Hz (can’t say for sure which one)

14. Beats are used in tuning • when tuning a guitar a beat frequency of 3 Hz is heard when comparing the sound from the guitar to 256 Hz tuning fork. The string is then slightly tightened and a beat frequency of 4 Hz is observed. • What is the guitar string’s frequency now?

15. Beats are used in tuning • when tuning a guitar a beat frequency of 3 Hz is heard when comparing the sound from the guitar to 256 Hz tuning fork. The string is then slightly tightened and a beat frequency of 4 Hz is observed. • What is the guitar string’s frequency now?260 Hz

16. Decibel Sound Level

17. it’s actually easy • intensity 10 (101) louder 10 dB higher • intensity 100 (102) louder 20 dB higher • intensity 1000 (103) louder 30 dB higher • intensity 10,000 (104) louder 40 dB higher • intensity 1,000,000 (106) louder 60 dB higher