Phy-125 Test 3

Front 1

A measure of the ability to cause some sort of change:

Back 1

Work / Energy

Front 2

Units of work / energy:

Back 2

Joules (J)

Front 3

The maximum variation of an acoustic variable:

Back 3

Amplitude

Front 4

List the acoustic variables:

Back 4

pressure, density, & particle motion

Front 5

How fast work is done or energy is created:

Back 5

Power

Front 6

Units of power:

Back 6

Watts (W)

Front 7

The ratio of power to area:

Back 7

Intensity

Front 8

The rebounding of a wave off a boundary between two mediums:

Back 8

Reflection

Front 9

The rebounding of a wave off of a smooth surface so that the reflected sound travels in one direction:

Back 9

Specular Reflection

Front 10

The rebounding of a wave off of a rough surface so that the reflected sound travels in many directions:

Back 10

Diffuse Reflection (Backscattering)

Front 11

The redirecting of sound in many directions:

Back 11

Scattering

Front 12

The redirection of sound in many directions for selective frequencies only:

Back 12

Rayleigh Scattering

Front 13

The passing of sound from one medium to another:

Back 13

Transmission

Front 14

The bending of a wave as it moves obliquely into a different medium:

Back 14

Refraction

Front 15

The separation of sound into its frequency components as a result of various degrees of bending as the sound enters a second medium:

Back 15

Dispersion

Front 16

The spreading out of sound as it passes through a small opening:

Back 16

Diffraction

Front 17

A medium's opposition to sound propagation:

Back 17

Impedance (Z)

Front 18

The ________ is the percentage of the sound intensity that is reflected off a surface.

Back 18

reflection coefficient (R)

Front 19

The ________ is the percentage of the sound intensity that passes into a second medium.

Back 19

transmission coefficient (T)

Front 20

The extent to which ultrasound is reflected:

Back 20

Echogenicity

Front 21

The reduction in amplitude of sound as it propagates through a medium:

Back 21

Attenuation

Front 22

_________ results in the conversion of sound energy into heat.

Back 22

Absorption

Front 23

The decibels lost per MHz of frequency per cm of travel:

Back 23

Attenuation rate

Front 24

The decibels lost per cm of travel:

Back 24

Attenuation coefficient

Front 25

A measure of the largest & smallest intensity that can be measured:

Back 25

Dynamic Range

Front 26

Impedance is the product of:

Back 26

(mass density in kg/m3)(wave speed in m/s)

Front 27

SI units of impedance:

Back 27

Rayls

Front 28

Typical values of impedance:

Back 28

1.25 MRayls - 1.75 MRayls

Front 29

Log formula for attenuation:

Back 29

dB = 10log(final intensity/initial intensity)

Front 30

Attenuation depends on what factors?

Back 30

medium, frequency, & distance

Front 31

Attenuation rate depends on what factors?

Back 31

Medium only

Front 32

Attenuation coefficient depends on:

Back 32

Medium & source

Front 33

AR of soft tissue:

Back 33

1/2

Front 34

AR of blood:

Back 34

1/8

Front 35

AR of muscle:

Back 35

1

Front 36

Wave speed in bone:

Back 36

3500 m/s (3.5 mm/microsecond)

Front 37

Wave speed in soft tissue:

Back 37

1540 m/s (1.54 mm/microsecond)

Front 38

Wave speed in lung:

Back 38

500 m/s (.5 mm/microsecond)