Chapter 7

Question 1

periodic back-and-forth motion that transmits energy

Answer 1

wave

Question 2

substance through which a wave travels

Answer 2

medium

Question 3

high point of a wave train

Answer 3

crest

Question 4

low point of a wave train

Answer 4

trough

Question 5

waves in which particles of the transmitting medium oscillate at right angles

Answer 5

transverse wave

Question 6

waves in which particles of the transmitting medium oscillate in the direction of wave motion

Answer 6

longitudinal wave

Question 7

portion of the longitudinal wave that is spread out

Answer 7

rarefaction pulse

Question 8

portion of the wave that is squeezed together

Answer 8

compression pulse

Question 9

length of a single wave

Answer 9

wavelength

Question 10

maximum distance that particles are displaced by a wave

Answer 10

amplitude

Question 11

inverse of a period; number of waves that pass a given point per unit time

Answer 11

frequency

Question 12

SI unit of frequency

Answer 12

hertz

Question 13

time needed for one wave cycle to pass

Answer 13

period

Question 14

what is directly proportional to both wavelength and frequency

Answer 14

speed

Question 15

change in the course of a wave as a result with an object or boundary

Answer 15

reflection

Question 16

what does the law of reflection state

Answer 16

angle of incidence equals angle of reflection

Question 17

spreading out of a wave after it passes through a narrow opening

Answer 17

diffraction

Question 18

bending of the path of a wave as a result in change of speed

Answer 18

refraction

Question 19

diffraction causes the wave to spread out evenly when the opening is roughly equal to ___ ___

Answer 19

one wavelength

Question 20

refracted waves always bend toward what?

Answer 20

the medium that slows it down

Question 21

temperature at which sound travels

Answer 21

331 m/s

Question 22

occurs when two or more waves meet

Answer 22

interference

Question 23

when a crest and trough with the same amplitude meet

Answer 23

complete destructive interference

Question 24

when a crest meets a trough

Answer 24

destructive interference

Question 25

when two crests or troughs meet

Answer 25

constructive interference

Question 26

vibrations traveling through a medium in the form of longitudinal pressure waves

Answer 26

sound

Question 27

in order for sound to travel, it needs a ___

Answer 27

medium

Question 28

strength of a sound wave

Answer 28

intensity

Question 29

effect of intensity on the way the human ear perceives sound

Answer 29

loudness

Question 30

used to measure sound intensity level

Answer 30

decibel

Question 31

effect of frequency on the way the human ear perceives sound

Answer 31

pitch

Question 32

sound that can be heard

Answer 32

audible

Question 33

pitches below the audible range

Answer 33

infrasonic sounds

Question 34

sounds with pitches above the audible range

Answer 34

ultrasonic sound

Question 35

change in frequency caused by an object's motion

Answer 35

Doppler effect

Question 36

main factor affecting the speed of sound

Answer 36

temperature

Question 37

speeds above the speed of sound

Answer 37

supersonic

Question 38

speeds below the speed of sound

Answer 38

subsonic

Question 39

noise a shock wave produces

Answer 39

sonic boom

Question 40

violent compression pulse

Answer 40

shock wave

Question 41

multiple reflections causing a persistence of sound

Answer 41

reverberation

Question 42

sound heard distinctly after being reflected from an object

Answer 42

echo

Question 43

developed to locate enemy submarines

Answer 43

sonar

Question 44

process of dissipating the energy of sound waves

Answer 44

absorption

Question 45

study of sound

Answer 45

acoustics

Question 46

series of organised sound waves that have deliberately been arranged

Answer 46

music

Question 47

random sound with no intended pattern

Answer 47

noise

Question 48

difference in pitch between two notes that has twice the frequency of the first note

Answer 48

octave

Question 49

two notes interfering harmoniously

Answer 49

consonance

Question 50

two notes interfering disagreeably

Answer 50

dissonance

Question 51

distance between two musical notes

Answer 51

interval

Question 52

a burst of loud sound pertaining to music

Answer 52

beat

Question 53

the low, dominant sound an instrument plays

Answer 53

fundamental

Question 54

sounds other than the fundamental an instrument plays

Answer 54

overtones

Question 55

The frequency relationships between the fundamental and overtones

Answer 55

harmonic series

Question 56

distinct sound of an instrument

Answer 56

timbre

Question 57

set of frequencies at which an object vibrates

Answer 57

natural frequencies

Question 58

when two frequencies are the same or nearly the same

Answer 58

resonance

Question 59

an opening to a hollow body

Answer 59

resonator