Physical Science Chapter 7

Question 1

a back and forth motion that transmits energy

Answer 1

wave

Question 2

a substance through which a wave transfers its energy

Answer 2

medium (media is plural)

Question 3

a portion of a wave that only has a crest or only a trough

Answer 3

wave pulse

Question 4

a wave in which particles of the transmitting medium oscillate at right angles to the direction of wave travel

Answer 4

transverse wave

Question 5

a series of waves

Answer 5

wave train

Question 6

high point on a wave

Answer 6

crest

Question 7

low point on a wave

Answer 7

trough

Question 8

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

Answer 8

longitudinal wave

Question 9

the pulse of a longitudinal wave in which particles of the transmitting medium are squeezed together

Answer 9

compression pulse

Question 10

the pulse of a longitudinal wave in which particles of the transmitting medium are spread out

Answer 10

rarefaction pulse

Question 11

a spring that is stretched or compressed will produce a restorative force that resists the stretching or compression

Answer 11

Hooke’s law

Question 12

an oscillation caused by a restorative force that is proportional to the displacement from equilibrium

Answer 12

simple harmonic motion

Question 13

the length of a single wave

Answer 13

wavelength

Question 14

the maximum distance that particles are displaced by a wave

Answer 14

amplitude

Question 15

the number of waves that pass a given point per unit time

Answer 15

frequency

Question 16

the time needed for one cycle of a repeating process like the swing of a pendulum or the passing of a wave

Answer 16

period

Question 17

the rate at which a wave travels through a medium

Answer 17

speed

Question 18

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

Answer 18

reflection

Question 19

waves that strike the boundary

Answer 19

incident waves

Question 20

waves that “bounce” off the boundary

Answer 20

reflected waves

Question 21

states that the angle of incidence equals the angle of reflection

Answer 21

law of reflection

Question 22

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

Answer 22

refraction

Question 23

the spreading out of a wave after it passes around an obstacle or through a narrow gap

Answer 23

diffraction

Question 24

the mutual reinforcement or cancellation that occurs when two or more waves meet

Answer 24

interference

Question 25

when two crests or two troughs meet

Answer 25

constructive interference

Question 26

when a crest meets a trough

Answer 26

destructive interference

Question 27

when waves completely cancel each other out

Answer 27

complete destructive interference

Question 28

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

Answer 28

sound

Question 29

the strength of a sound wave

Answer 29

intensity

Question 30

the effect of intensity on the way the human ear perceives sound

Answer 30

loudness

Question 31

a measure of sound intensity that better reflects perceived loudness

Answer 31

sound intensity level

Question 32

the unit of sound intensity

Answer 32

Decibel

Question 33

the effect of frequency on the way the human ear perceives sound

Answer 33

pitch

Question 34

sound in the audible frequency range of human hearing

Answer 34

audible sound

Question 35

sounds with pitches below the audible range

Answer 35

infrasonic

Question 36

sounds with pitches above the audible range

Answer 36

ultrasonic

Question 37

the change in frequency caused by an object’s motion

Answer 37

Doppler effect

Question 38

Speed of sound at 0℃ is ___

Answer 38

331 m / s

Question 39

a speed above the speed of sound

Answer 39

supersonic

Question 40

a speed below the speed of sound

Answer 40

subsonic

Question 41

a violent compression pulse produced by constructive interference between waves produced by an object moving at supersonic speeds

Answer 41

shock wave

Question 42

a loud noise caused by the shock wave from traveling at supersonic speeds

Answer 42

sonic boom

Question 43

multiple reflections that cause persistence of sound

Answer 43

reverberation

Question 44

a sound heard distinctly after being reflected from some object

Answer 44

echo

Question 45

a system that emits sound waves underwater and analyzes the echoes reflected from submerged objects to determine the size, distance, and direction

Answer 45

sonar

Question 46

the procedure for calculating distance by measuring the time interval that elapsed between the sending of a sound wave and the return of an echo

Answer 46

echo ranging

Question 47

the process of dissipating the energy of sound waves in matter

Answer 47

absorption

Question 48

the study of sound

Answer 48

acoustics

Question 49

a series of organized sound waves with specific pitches that have been deliberately arranged

Answer 49

music

Question 50

random sound with no intended pattern

Answer 50

noise

Question 51

a sound of definite pitch

Answer 51

note

Question 52

the difference in pitch between a musical note and a second note that has twice the frequency of the first note

Answer 52

octave

Question 53

the result of two musical notes interfering harmoniously

Answer 53

consonance

Question 54

the result of two musical notes interfering in a disagreeable way

Answer 54

dissonance

Question 55

the distance between two notes

Answer 55

interval

Question 56

a burst of louder sound occurring when interfering sound waves are perceived as a single pulsating sound

Answer 56

beat

Question 57

the lowest-frequency of the different sounds produced when an instrument plays a note

Answer 57

fundamental

Question 58

any of the sounds that are produced when an instrument plays a musical note and that are at higher frequencies than the fundamental

Answer 58

overtone

Question 59

the series showing the frequency relationships between a fundamental and its overtones

Answer 59

harmonic series

Question 60

the sound quality of a musical instrument

Answer 60

timbre

Question 61

any frequency in the set of frequencies at which an object vibrates

Answer 61

natural frequency

Question 62

a situation in which a driving frequency of an object is the same as or nearly the same as one of the object’s natural frequencies

Answer 62

resonance

Question 63

an opening to a hollow body that is next to the strings or membrane

Answer 63

resonator

Question 64

the time it takes for a wave to pass a point

Answer 64

period

Question 65

the inverse of a period

Answer 65

frequency

Question 66

the main factor affecting the speed of sound in air

Answer 66

temperature

Question 67

formula for frequency

Answer 67

f = N / t (frequency = number of waves / time)

Question 68

formula for speed

Answer 68

v = λf (speed = wavelength x frequency)

Question 69

formula for period

Answer 69

T = t / N (period = time / number of waves)