Physics Soundwaves Part 1

Question 1

traveling

Answer 1

Propagating

Question 2

the capability to do work

Answer 2

energy

Question 3

propagating variation

Answer 3

wave

Question 4

A _____ is a propagating disturbance that moves energy from one location to another

Answer 4

wave

Question 5

_____ is a wave

Answer 5

sound

Question 6

Sound is a particular type of _____

Answer 6

wave

Question 7

Quantities of these variations are called acoustic variables

• _____
• _____
• Particle _____
• _____

Answer 7

density
pressure
motion
temperature

Question 8

Particles _____ back and forth as sound waves travel through the medium

Answer 8

oscillate

Question 9

Sound waves require a _____

Answer 9

medium

Question 10

They cannot travel through a _____

Answer 10

vacuum

Question 11

Sound is a mechanical _____ (compression) wave

Answer 11

longitudinal

Question 12

P waves are _____ waves

Answer 12

longitudinal

Question 13

S waves are _____ waves

Answer 13

transverse

Question 14

Components of an Ultrasound Wave

1. Compression
   - Region of _____ pressure and _____ in a longitudinal wave
   - Corresponds to a sine wave _____
2. Rarefaction
   - Region of _____ pressure and _____ in a longitudinal wave
   - Corresponds to a sine wave _____
3. Cycle - _____ complete variation of an acoustic variable
4. Y Axis - typically represents _____ (strength) of an acoustic variable
5. X Axis -typically represents _____ or _____

Answer 14

high
density
peak
low
density
trough
one
amplitude
time
distance

Question 15

Wave Parameters

• _____
• _____
• _____

Answer 15

Frequency
Period
Wavelength

Question 16

_____ = The number of cycles that occur in one second

Answer 16

frequency

Question 17

Frequency

Determined by the _____ source

Affects _____ and _____ Resolution

Answer 17

sound
penetration
axial

Question 18

Frequency

_____/_____ = 1 Hertz

_____ Hz = 1 kHz

_____ Hz = 1 MHz

Humans are capable of hearing frequencies between _____ and _____ Hz

Answer 18

cycle
second
1,000
1,000,000
20
20,000

Question 19

Frequency

Frequencies > _____Hz = ULTRASOUND

Typical in Diagnostic Medical Ultrasound

___-___ MHz through ___-___ MHz

Great _____ = Lousy _____ resolution
Great _____ resolution = Lousy _____

Limits defined by
_____ resolution and _____

Answer 19

20,000
1-2
10-20
penetration
axial
axial
penetration
axial
penetration

Question 20

Frequency

Frequency (Hz) = 1/___(sec)

_____ and _____ are RECIPROCALS

Higher frequency = lower period

Answer 20

period
period
frequency

Question 21

Frequency

Frequency _____ = Period _____
Period _____ = Frequency _____

Period and Frequency are _____ proportional

Answer 21

increases
decreases
increases
decrease
inversely

Question 22

Period

Length of time to complete _____ cycle

Time from start of _____ cycle to start of the next cycle

Determined by the _____ SOURCE

Answer 22

one
one
SOUND

Question 23

Period

Unit = _____, (microsecond)

Answer 23

second

Question 24

Period

Period = 1/____ (MHz)

_____ and _____ are RECIPROCALS

Answer 24

frequency
period
frequency

Question 25

Period Period _____ = Frequency _____ Period _____ = Frequency _____ Period and Frequency are _____ proportional

Answer 25

``` decreases increases increases decrease inversely ```

Question 26

Wavelength _____ of space over which one cycle occurs Determined by _____ source and _____

Answer 26

length sound medium

Question 27

Wavelength Unit = _____, mm (any distance measurement) 1 mm = _____ m Common US wavelength in ST (Soft Tissue) _____-_____ mm

Answer 27

meters 0. 001 0. 1 0. 8

Question 28

Wavelength Wavelength (mm) = Propagation _____/_____ (MHz) Wavelength = c/f For Soft Tissue: Wavelength = _____/_____ (MHz)

Answer 28

``` speed frequency c f 1.54 frequency ```

Question 29

Wavelength If: Wavelength = _____/_____ As: Wavelength _____ - Frequency _____ Wavelength _____ - Frequency _____

Answer 29

``` c f increase decrease decrease increase ```

Question 30

Wavelength Wavelength and Frequency are _____ proportional

Answer 30

Inversely

Question 31

Propagation Speed a.k.a. Acoustic Velocity _____ = is the RATE at which sound travels through a medium vs _____ = is the RATE AND DIRECTION at which sound travels through a medium

Answer 31

speed | velocity

Question 32

Sound Source = _____ and _____ Medium = Propagation _____ Sound Source and Medium = _____

Answer 32

frequency, period speed wavelength

Question 33

Propagation _____ = The speed at which sound can travel through a medium Units: _____/_____ Determined ONLY by the _____

Answer 33

speed meters second MEDIUM

Question 34

Propagation Speed All _____, regardless of _____, travels at the same speed through any specific medium Speed of sound in SOFT TISSUE 1.54 km/s 1,540 m/s 1.54 mm/ms 3,500 mph

Answer 34

sound | frequency

Question 35

Propagation Speed Propagation Speed (m/s) = _____(Hz) x _____(meters)

Answer 35

frequency | wavelength

Question 36

Propagation Speed What is it about the medium that determines propagation speed? Medium _____ and _____ _____ is the resistance of a material to compression _____ is the concentration of matter

Answer 36

stiffness density stiffness density

Question 37

Propagation Speed Rule of Thumb: Stiffness _____ - Speed _____ Density _____ - Speed _____

Answer 37

increases increases increases decreases

Question 38

Propagation Speed Associated with stiffness are 2 additional factors _____ and _____ _____ is the ability of an object to return to its original space and volume after a force is no longer acting on it -opposite of stiffness- _____ if the fractional decreases in volume when pressure is applied -opposite of stiffness-

Answer 38

elasticity compressibility elasticity compressibility