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1. name 4 acoustic variables
• pressure
• density
• temperature
• particle motion
2. what is nyquist criteria
• f(max)=f sampling
• 2
3. what is propigation velocity in soft tissue
1540 m/s
4. how many mu sec does it take sound to travel 1cm
6.5 mu sec
5. how long does it take to image to a depth of 1cm
• 6.5 mu sec x 2cm (travel time)=
• 13mu sec
6. what is density represented by?
p
7. what is density equasion
• density(p) = mass kg
• volume m3
8. What are the 4 wave parameters
• frequency/period
• wavelenght
• propagation velocity
• amplitude
9. what is frequency/ period determined by and what are its units
wave source

cycles/second or HZ
10. what is wavelength determined by
wave source and medium

any form of distance mm
11. what is propagation velocity determined by and what are its units
medium

m/s
12. what is amplitued determined by and what is its units
• wave source but decreases with distance
• volts or Decibels dB
13. what is the equasion for wavelength
• wavelenght = propigation velocity
• frequency

lamda= c/f
14. define amplitude
size, strength, or volume
15. what is amplitued equasion
max- mean

mean-min

• max-min
• 2
16. what is range of infrasound
<20Hz
17. What is range of Ultrasound
>20 kHz
18. What is range of audible sound
20Hz-20kHz
19. What is formula for bulk modulus?
• stress
• strain

• change in pressure
• change in volume
• volume
20. High bulk modulus material is
• incompressible
• inelastic
• stiff
21. low bulk modulus material is
• compressible
• elastic
• not stiff
22. what is equasion for prop v as related to Bulk modulus
• c=square root of B mod
• p (density)
23. what is prop v in air
331
24. What is prop v in bone?
4080 m/s
25. what is prop v in soft tissue?
1540 m/s
26. what is prop v range for gases
ie... air, helium, hydrogen
331-1286 m/s
27. what is prop v range for liquids
ie... water, alcohol
1130-1530 m/s
28. what is prop v range for solids
1322- 12,000 m/s
29. higher bulk modulus does what to prop v
increase
30. lower bulk modulus does what to prop v
decreases
31. power is directly proportional to
voltage2 or Amplitude2
32. What does the transmit power button control?
changes the signals amplitude
33. what are alternitive names for transmit power?
• acoustic power
• output power
• transmit gain
• power gain
• output intensity
• acoustic output
34. intensity is directly proportional to what?
power
35. what is intensity equasion?
• Intensity= power watts
• Beam area m2

• OR amplitude2
• beam area
36. what is the power equasion for dB
• dB= 10 x log(Pf
• Pi)

• Pf is power final
• pi is power initial
37. what is the amplitude equasion for dB
• dB= 20*log (Af)
• Ai

• af is amplitude final
• ai is amplitude initial

### Card Set Information

 Author: melissausp ID: 70449 Filename: us physics Updated: 2011-03-03 17:43:35 Tags: us physics Folders: Description: chapter 2 Show Answers:

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