1 Ch 2: Sound

Question 1

acoustic propagation properties

Answer 1

the effects of the medium upon the sound wave

Question 2

biologic effects

Answer 2

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

Question 3

compressed

Answer 3

squeezed together

Question 4

rarefied

Answer 4

stretched apart

Question 5

Sound travels in a (straight/crooked) line.

Answer 5

straight

Question 6

Sound waves are (longitudinal/transverse) waves.

Answer 6

longitudinal

Question 7

These are used to distinguish between sound waves and other types of waves.

Answer 7

acoustic variables

Question 8

Name the acoustic variables.

Answer 8

pressure, density, distance

Question 9

Define pressure

Answer 9

concentration of force in an area - units: pascals (Pa)

Question 10

Define density

Answer 10

concentration of mass in a volume - units: kg/cm^3

Question 11

Define distance

Answer 11

measure of particle motion - units: cm, mm

Question 12

These are required to completely describe the features of a sound wave.

Answer 12

acoustic parameters

Question 13

Name the acoustic parameters.

Answer 13

period, frequency, amplitude, power, intensity, wavelength, propagation speed

Question 14

transverse wave

Answer 14

wave in which the particles move in a direction that is perpendicular to the direction fo the wave.

Question 15

longitudinal wave

Answer 15

wave in which the particles move in the same direction of the wave.

Question 16

in-phase

Answer 16

when the peaks and troughs of a pair of waves occur at the same time and place

Question 17

out-of-phase

Answer 17

when the peaks and troughs of a pair of waves occur at a different time and place

Question 18

interference

Answer 18

when a wave combines with another wave and loses its individual characteristics

Question 19

constructive interference

Answer 19

when a pair of in-phase waves combine to form a greater amplitude than either of its components

Question 20

destructive interference

Answer 20

when a pair of out-of-phase waves combine to form a lesser amplitude of its components

Question 21

Both constructive and destructive interference occurs when…

Answer 21

two waves of differing frequencies combine.