Ch. 2 Physics: Sound

Question 1

What is a mechanical, longitudinal wave that moves through a medium as the result of vibrations?

Answer 1

Sound wave

Question 2

True or false:
Sound requires a medium through which to travel.

Answer 2

True

Question 3

True or false:
Sound can travel in a vacuum (space around us).

Answer 3

False

Question 4

True or false:
The medium stays fixed.

Answer 4

True

Question 5

Vibrations move from one location to the next.

Answer 5

Sound propagation

Question 6

In ultrasound, what is the medium?

Answer 6

Body tissue or organs being imaged

Question 7

True or false:
Sound waves travel in a straight line

Answer 7

True

Question 8

What does sound carry?

Answer 8

Energy

Question 9

What are sound waves also referred to as?

Answer 9

Acoustical waves

Question 10

Particles of a medium move in the same direction (parallel) to the direction that the sound wave is propagating is called what?

Answer 10

Longitudinal waves

Question 11

Particles of a medium move in a direction perpendicular to the direction of the sound wave is called what?

Answer 11

Transverse waves

Question 12

True or false:
Sound waves are pressure waves.

Answer 12

True

Question 13

How does the sound wave propagate through a medium?

Answer 13

By a series of compressions and rarefactions of molecules in the path of the sound.

Question 14

What does it mean when the sound wave is compressed?

Answer 14

Squeezed together

Question 15

What does it mean when the sound wave is rarefied?

Answer 15

Stretched apart

Question 16

Acoustic propagation properties describes the effects of what upon a sound wave?

Answer 16

Medium

Question 17

Will stiff tissue speed or slow the sound wave?

Answer 17

Speed up

Question 18

Will air slow or speed up the sound wave?

Answer 18

Slow down

Question 19

What effects the sound wave upon the tissue through which it passes?

Answer 19

Biological effects

Question 20

Transmitted sound waves over tissues will heat up the tissue being imaged is an example of what?

Answer 20

Biological effects

Question 21

What are the 3 acoustic variables?

Answer 21

Pressure
Density
Distance

Question 22

If any of the acoustic variables have a rhythmic oscillation, then the wave is considered what?

Answer 22

A sound wave

Question 23

What is the concentration of mass in a volume?

Answer 23

Density

Question 24

What is the units for density?

Answer 24

kg/cm^3

Question 25

What is the concentration of force in an area?

Answer 25

Pressure

Question 26

What is the units for pressure?

Answer 26

pascals (Pa)

Question 27

What is a measure of particle motion?

Answer 27

Distance

Question 28

What are the units for distance?

Answer 28

cm feet mile

Question 29

What does the acoustic parameters of a sound wave do?

Answer 29

Describe the features

Question 30

What are the 7 acoustic parameters?

Answer 30

Frequency Intensity Power Period Propagation speed Amplitude Wavelength

Question 31

What type of waves demonstrate matching "peaks and valleys"? They occur at the same places, at the same time.

Answer 31

In-phase waves

Question 32

What types of waves demonstrate "peaks and valleys" occurring at different times and/ or different locations?

Answer 32

Out-of-phase waves

Question 33

What occurs when multiple waves exist at the same time and location, then combine to form one wave?

Answer 33

Interference

Question 34

What are the 2 types of interference?

Answer 34

Constructive Destructive

Question 35

What type of interference is two in-phase waves that result in a higher amplitude single wave?

Answer 35

Constructive

Question 36

What typw of interference is two out-of-phase waves that result in a lower amplitude single wave?

Answer 36

Destructive

Question 37

True or false: When out-of-phase waves of equal amplitude interfere, they will concel each other out.

Answer 37

True

Question 38

What is the result when waves of different frequencies interfere with each other?

Answer 38

Constructive and destructive interference