0
Upcoming SlideShare
×

Thanks for flagging this SlideShare!

Oops! An error has occurred.

×
Saving this for later? Get the SlideShare app to save on your phone or tablet. Read anywhere, anytime – even offline.
Standard text messaging rates apply

# Ch12 (2)

296

Published on

Published in: Education
0 Likes
Statistics
Notes
• Full Name
Comment goes here.

Are you sure you want to Yes No
• Be the first to comment

• Be the first to like this

Views
Total Views
296
On Slideshare
0
From Embeds
0
Number of Embeds
0
Actions
Shares
0
5
0
Likes
0
Embeds 0
No embeds

No notes for slide

### Transcript

• 1. Chapter 12 Waves and Sound
• 2. Ch12.1 Properties of sound
• 3. Compression Rarefaction Simple sinusoidal (sin) vibration– pure tone
• 4. 疏 密  Wave-front surface 波前
• 5. &nbsp;
• 6. &nbsp;
• 7. Wave in time domain and space domain 空間 位置 z 時間 z=0
• 8. Compression Rarefaction Intensity Frequency Simple sinusoidal (sin) vibration– pure tone Speed of sound at 20℃, in air 3.3×10 4 cm/sec in water 1.4×10 5 cm/sec Total pressure P P a : ambient air pressure P o : maximum pressure change due to the sound wave Intensity I ~ I : amount of energy transmitted by a sinusoidal sound wave per unit time through each unit area ⊥ the direction of sound propagation ρ: density of medium
• 9. Ch12.2 Some properties of waves Ch12.2.1 Reflection and refraction
• 10. Ch12.2.2 Interference In phase Constructive interference Out of phase Deconstructive interference R=A+B Same frequency
• 11. Standing wave
• 12. close open
• 13. Standing wave Resonant frequency Ch12.2.3 Diffraction
• 14. Ch12.3 Hearing and Ear
• 15. Figures from Urone, College physics Also see Text on p175
• 16. Ch 12.3.1Performance of the Ear Loudness, Pitch, Quality cps cycle per second frequency = + + +
• 17. frequency/ pitch
• 18. <ul><li>C D E F G A B C ’ </li></ul><ul><li>Do Re Mi Fa Sol La Ti Do </li></ul>中央 C f C =256Hz 中央 C 之上的 A f A =440Hz
• 19. Ch12.3.3 Intensity and Loudness For human ear Threshold of hearing 10 -16 W/cm 2 , at 3000Hz Threshold of pain 10 -4 W/cm 2 Ex 12-3
• 20. Also see Text on p175 Resonance at 3000Hz, Pressure is increased by another factor of 2 . Mechanical Advantage MA
• 21. Ch 12.4 Bats and Echoes Ex 12-6
• 22. Ch 12.5 Sound produced by animal Ch 12.6 Acoustic Trap Rattlesnake Vocal cord
• 23. Ch 12.7 Clinical uses of Sound Ch12-8 Ultrasonic Wave
• 24. &nbsp;
• 25. Doppler effect(1)
• 26. Car moving  wavefront profile change
• 27. Car moving  wavefront profile change 右邊的人聽到的 :
• 28. Car stop  wavefront profile did not change 右邊的人聽到的 :
• 29. 利用超音波及都卜勒效應 量測生物體內液體流速 Urone, College Physics Ex16.7 A diagnostic ultrasound echo is reflected from moving blood and returns with a frequency 500Hz higher than its original 2MHz.The speed of the ultrasound is 1540m/s. (a)What is the velocity of the blood? (b) What frequency does the blood receive?
• 30. Self-practice <ul><li>Exercise 12-3, 12-6, 12-8 </li></ul>