Ch. 17 Mechanical Waves And Sound

Front 1

Name 2 parts of a wave

Back 1

Crest, trough,

Front 2

Medium

Back 2

Matierals through which a wave travels.

Front 3

A mechanical wave is created when a source of energy causes a vibration to travel through a medium. (True or False)

Back 3

True

Front 4

Three main types of mechanical waves are?

Back 4

Transverse waves, longitudinal waves surface waves, and surface waves.

Front 5

Crest

Back 5

The highest point of a wave.

Front 6

Trough

Back 6

Lowest point of a wave.

Front 7

Transverse wave

Back 7

A wave that causes the medium to vibrate at the right angles to the direction in which waves travel.

Front 8

Compression

Back 8

Particles in a medium are spaced together

Front 9

Rarefraction

Back 9

Area where the particles in a medium are spread out.

Front 10

Longitudinal wave

Back 10

Wave in which the vibration of the medium is parellel to the direction the wave travels.

Front 11

Surface wave

Back 11

Wave that travels along a surface separating two media.

Front 12

Periodic motion

Back 12

Any motion that repeats at regular time intervals.

Front 13

Frequency

Back 13

Number of complete cycles in a given time.

Front 14

Hertz

Back 14

Frequency is measured in cycles per second.

Front 15

A wave's frequency does not equals the frequency of the vibrating source producing the wave. ( True False)

Back 15

False

Front 16

Wavelength

Back 16

Distance between a point on one wave and the same point on the next cycle of the wave.

Front 17

Increasing the frequency of a wave ________ its length.

Back 17

decreases

Front 18

Speed= Wavelength * Frequency

Back 18

Speed of waves

Front 19

One end of a rope is vibrated to produce a wave with a wavelength of .25 meters. The frequency of the wave is 3 hertz. What is the speed of the wave.

Back 19

.25m*3Hz= .75m/s

Front 20

If you assume that waves are traveling at a constant speed, then the wave length is inversely proportional to frequency. (True, False)

Back 20

True

Front 21

Amplitude

Back 21

A wave is the maximum displacement of the medium from its rest position.

Front 22

The more energy a wave has the __________ is its amplitude.

Back 22

greater

Front 23

Reflection

Back 23

When a wave bounces off a surface that it cannot pass through.

Front 24

Reflection does not change the speed or frequency of a wave, but the wave can be flipped upside down. (True, False)

Back 24

True

Front 25

Refraction

Back 25

Bending of a wave as it enters a new medium at an angle.

Front 26

When a wave enters a medium at an angle, refraction occurs because one side of a wave moves more _________ than the other side.

Back 26

Slowly

Front 27

Diffraction

Back 27

Bending of a wave as it moves around an obstacle or passes through a narrow opening.

Front 28

A wave diffracts more if its wavelength is small compared to the size of an opening of obstacle. (True, False)

Back 28

False

Front 29

Interferance

Back 29

Occurs when two or more waves overlap and combine together.

Front 30

Two types of interference.

Back 30

Constructive interference
destructive interference.

Front 31

Constructive interference

Back 31

Occurs when two or more waves combine to produce a wave with a larger displacement.

Front 32

Destructive interference

Back 32

Occurs when two or more waves combine to produces a wave with a smaller displacements.

Front 33

Standing wave

Back 33

A wave that appears to stay in one place.

Front 34

Node

Back 34

Point standing wave that has no displacement from the rest position.

Front 35

Antinode

Back 35

Point where a crest or trough occurs misway between two nodes.

Front 36

Astanding wave forms only if all the wavelength or half a wavelength fits exactly into the length of the vibrating cord. (True, False)

Back 36

False