Physical Science: chapter 17 Mechanical Waves and Sounds

mechanical wave

a disturbance that transmits energy through matter space

a source od energy causes a vibration to travel through a medium

a mechanical wave is created when...

medium

the material through which a wave travels

solid, liquid, or gas

a medium can be a...

how the medium moves in relation to the movement of the wave

waves are classified by...

transverse waves and longitudinal waves

the 2 types of waves

transverse wave

a wave in which the medium moves at right angles to the direction in which the wave travels

line of origin

the original position of the medium before the wave passes through

crest

the highest point of the wave (highest energy)

troph

the lowest point of the wave (lowest energy)

amplitude

the distance from the line of original to the top of a crest (or the bottom of a troph)

wavelength

the distance from a crest to a crest (or a troph to a troph)

wavelength

the distance from a point on one wave length to the same point on the next wave

longitudinal wave

a wave in which the medium moves in the same direction as the movement of the wave

compression, rarefaction, wavelength, amplitude

parts of a longitudinal wave...

compression

an area where the particles of the medium are close together

rarefaction

an area where the particles of the medium are far apart

wavelength

the distance between 2 compression or 2 rarefactions

amplitude

the width of a compression or rarefaction

frequency

the number of waves cycles that pass a point in a given amount of time

hertz (Hz)

frequency is measured in...

waves/second

hertz=

1 crest and 1 troph

for it to be a transverse wave it must have...

1 compression and 1 rarefaction

for it to be a longitudinal wave it must have...

meters/second

the unit for speed is...

wave interaction

when a wave encounters a barrier or another eave, they exhibit certain properties

reflections

when a wave bounces off a hard, flat surface

diffraction

the bending of a wave as it moves around an obstacle or through a narrow opening

refraction

the bending of a wave as it enters a new medium at an angle (due to a change in speed)

interference

when a wave interaction with another wave types of interference

constructive interference

when 2 crest or 2 compressions meet

destructive interference

when the crest of one wave meets the troph of another, or when a compression meets a rarefaction

constructive interference and destructive interference

the 2 types of interference

good

constructive interference (good or bad)

bad

destructive interference (good or bad)

vibrating object

sound is produced by a...

longitudinal

sound waves are... (transverse or longitudinal)

temperature, medium, elasticity, density

factors affecting the speed of sound

faster

The higher the temperature the... the speed of sound

solids

sound traves fastest through (solids, liquids, or gases)

gases

sound travels slowest through (solids, liquids, or gases)

elasticity

how fast the particles of a substance can move and return to their original position

solids

which are the most elastic: solids, liquids, gases

gases

which are the least elastic: solids, liquids, gases

faster

the higher the density of the substance, the... the speed of a sounds moves through that substance (particles are closer together)

intensity

loudness or volume

decibels (db)

intensity is measured in...

120 db

threshold for pain

pitch

how high or low a sound is (not as in volume)

higher

the faster the vibration the... the pitch

hertz (hz)

pitch is measured in