1. Photo Album
by Robert MacKay

2. Sound waves are longitudinal waves

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

8. 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.

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

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

11. 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.

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

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

14. 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.

28. Beats
The beat frequency is the difference between two frequencies.

29. 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?

30. 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)

31. 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?

32. 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

34. Decibel Sound Level

35. it’s actually easy intensity 10 (101) louder 10 dB higher