Ch. 2 Sound

Question 1

All waves carry _______ from one location to another.

Answer 1

All waves carry energy from one location to another

Question 2

Sound is a ___________________ wave, in which particles in the medium move

Answer 2

Sound is a mechanical wave, in which particles in the medium move

Question 3

Sound cannot travel though a ________________________, it must travel through a medium

Answer 3

Sound cannot travel through a vacuum it must travel through a medium

Question 4

When sound travels through a medium, molecules are alternately _______________________ and ____________________

Answer 4

When sound travels through a medium, molecules are alternately compressed (squeezed together) and rarefied ( stretched apart)

Question 5

Sound travels in a ________________ line

Answer 5

Sound travels in a straight line

Question 6

Sound waves are _______________________ waves

Answer 6

Sound waves are longitudinal waves

Question 7

______________ ______________________ ________________ are the effects of the medium upon the sound wave

Answer 7

acoustic propagation properties are the effects of the medium upon the sound wave

Question 8

__________________ effects are the effects of the sound wave upon the biologic tissue through which it passes

Answer 8

Biologic effects are the effects of the sound wave upon the biologic tissue through which it passes

Question 9

What are the 3 acoustic variables?

Answer 9

1. Pressure
2. Density
3. Distance

Question 10

_____________________ is the concentration of force in an area

Answer 10

pressure is the concentration of force in an area

Question 11

___________________ is concentration of mass in a volume

Answer 11

density is concentration of mass in a volume

Question 12

______________________ is the measure of particle motion

Answer 12

distance is the measure of particle motion

Question 13

What are the units of pressure?

Answer 13

Pascals (Pa)

Question 14

What are the units of density?

Answer 14

kg/mL and kg/cm^3

Question 15

What are the units of distance?

Answer 15

cm, feet, mile, mm, etc.

Question 16

Sound waves are also known as _______________________ waves

Answer 16

Sound waves are also known as acoustic waves

Question 17

What are the 7 acoustic parameters?

Answer 17

1. Period
2. Frequency
3. Amplitude
4. Power
5. Intensity
6. Wavelength
7. Propagation speed

Question 18

In a ______________________wave, particles move in a direction that is perpendicular to the direction that the wave propagates

Answer 18

In a transverse wave particles move in a direction that is perpendicular to the direction that the wave propagates

Question 19

In a ___________________________ wave particles move in the same direction that the wave propagates

Answer 19

In a longitudinal wave particles move in the same direction that the wave propagates

Question 20

A pair of waves are considered _________________ when their peaks (maximum values) occur at the same time and at the same location.

Answer 20

A pair of waves are considered in-phase when their peaks (maximum values) occur at the same time and at the same location

Question 21

When two waves are _______________________ their peaks occur at different times, and so do their troughs.

Answer 21

When two waves are out-of-phase their peaks occur at different times, and so do their troughs.

Question 22

When on occasion, multiple beams arrive in an identical location at the same time the waves loose their individual characteristics and form a single wave: this combination is called ______________________________

Answer 22

When on occasion, multiple beams arrive in an identical location at the same time the waves loose their individual characteristics and form a single wave: this combination is called Interference

Question 23

Both in-phase and out-of-phase wave pairs undergo ______.

Answer 23

interference; however they combine differently

Question 24

A pair of in-phase waves results in the formation of a single wave of greater amplitude than either of its components. This combination is called ________________________ interference.

Answer 24

A pair of in-phase waves results in the formation of a single wave of greater amplitude than either of its components. This combination is called constructive interference

Question 25

______________________ interference is where the resulting wave is larger than either of its components

Answer 25

*constructive interference* is where the resulting wave is larger than either of its components

Question 26

A pair of out-of-phase waves results in the formation of a single wave of lesser amplitude than at least one of its components. This combination is called _________________________ interference.

Answer 26

A pair of out-of-phase waves results in the formation of a single wave of lesser amplitude than at least one of its components. This combination is called *destructive interference*

Question 27

__________________________ interference is where the resultant wave is smaller than one of its components

Answer 27

*destructive interference* is where the resultant wave is smaller than one of its components

Question 28

When two out-of-phase waves are of equal amplitude, _______________________ _______________________ interference may occur

Answer 28

When two out-of-phase waves are of equal amplitude, *complete destructive interference* may occur

Question 29

What do waves transfer from one location to another? A. matter B. molecules C. energy D. water

Answer 29

C. waves carry energy from place to place

Question 30

Which of the following best describes sound waves? A. a series of compression's and rarefractions B. waves that are heard by man C. movement of molecules and energy from one location to another D. waves that are used to make images of anatomy

Answer 30

A. sound waves are a series of compressions and rarefactions

Question 31

Which of the following terms does not belong with the others? A. compression B. region of high density C. region of high pressure D. wide molecular spacing

Answer 31

D does not belong

Question 32

Variations in all of the following identify specific waves as acoustic waves except: A. pressure B. parameters C. density D. acoustic variables

Answer 32

B parameters

Question 33

All of the following are true of sound waves except: A. they are acoustic B. they are pressure waves C. they are transverse D. they move energy

Answer 33

C. sound waves are longitudinal, not transverse

Question 34

All of the following are acoustic parameters except: A. pressure B. period C. propagation speed D. frequency

Answer 34

A. pressure is an acoustic variable, not a parameter

Question 35

Which of the following best describes sound waves? A. transverse, pressure waves B. transverse, longitudinal waves C. longitudinal waves, out-of-phase waves D. longitudinal, pressure waves

Answer 35

D. longitudinal, pressure waves best describe sound waves

Question 36

Two waves are traveling in a medium and arrive at a location at the same time. What event takes place? A. constructive interference B. destructive interference C. interference D. reflection

Answer 36

C. When two waves are traveling in a medium and arrive at a location at the same time. Interference takes place

Question 37

Which types of waves will exhibit both constructive and destructive interference? A. waves of different amplitude B. a pair of longitudinal waves C. waves of different frequency D. out-of-phase waves

Answer 37

C. both constructive and deconstruction interference occurs with waves with different frequencies

Question 38

What units are used to report the pressure of a sound beam? A. pounds B. centimeters C. pascals D. kg/cm

Answer 38

C. pressure is appropriately reported with units of pascals, abbreviated Pa

Question 39

True or False? Acoustic variables allow us to determine which waves are sound waves and which are not.

Answer 39

True

Question 40

True or False? Acoustic parameters are used to describe the features of sound waves

Answer 40

True