sound waves
human ear has a range of
20 Hz to 20,000 Hz
in air speed of sound is around ____ at room temp
340 m/s
sound
a form of energy that causes molecules of a medium to vibrate back and forth
a sound wave with many compressions will have...
a greater amplitude compared to waves with fewer compressions because more compressions= higher air pressure which equals higher amplitude
if source of sound moves away, waves reach observer later causing ...
a lower frequency
resonance
ability of an object to vibrate by absorbing energy in its natural frequency
ultrasonic
above 20,000 Hz
sound is slowest in...
air
amplitude is the measure of
amt of energy moving
rarefactions
area of low pressure air
compressions
areas of high pressure air
why there is not a sound in a vacuum (space)?
because there are not particles to vibrate
why is sound transmitted faster in solids than liquids?
because these materials are more elastic
infrasonic
below 20 Hz
bigger amp=
bigger amt of energy
elastic
can return to original shape
doppler effect
change in frequency and pitch of a sound due to motion of either the sound source or observer
two ways sound waves combine
constructively and destructively
the number of waves passing a point in a second is called
cycles per second or hertz
when out off hate, sound is softer..
dead spots can occur
intensity is measured in a unit called
decibel dB
natural frequency
every medium has its own frequency of vibrations
pitch is determined by
frequency
compressions are areas of
high pressure
the compressions (dark areas) represent..
high pressure can can be shown as a crest
faster the frequency=
higher pitch
increased pitch=
higher sound
how does temp effect sound
higher temp causes sound to travel faster
what does pitch depend on?
how fast the molecules of a medium vibrate which depends on the frequency of waves
since pitch is such a close proxy for frequency, the pitch of a musical note is determined by...
how quickly the sound wave is making the air vibrate
when in phase the intensity of sound is..
increased
what can cause permanent damage/hearing loss?
long exposure to 100 dB or greater sound levels
what is the effect of greater amplitude of a sound wave?
louder sound
what does intensity determine?
loudness of sound
rarefactions are areas of
low pressure
the rarefactions (light areas) represent ...
low pressure which can be shows as a trough
beats
phenomenon caused by combination of 2 waves of slightly different frequencies. this causes intensity to vary
when the frequency of sound waves increases what also increases?
pitch
if source of sound moves toward observer, waves are generated from....
points that are closer and closer
timbre
quality of sound caused by blending of pitches
longitudinal waves
series of compressions and rarefactions
longitudinal waves can be represented with a ....
sine wave to show the difference in pressure
if there are no molecules then there is no....
sound
shape a sound wave is sent out in
spherical shape
every object has a natural frequency and if it matches the natural frequency...
the amplitude is increased
what is intensity of a sound determined by?
the amplitude of the sound wave.
more densely packed the particles are,,
the bigger the amp
why does speed increase as temp bc
the molecules of the air are moving faster and bump into each other more often. Speed also increases slightly with water vapor in the air (more humid)
the pitch (frequency) of a sound can change if..
the speed of sound changes
resonance examples
the vibrations of a sound board of a violin, the note you get when you blow into a half full bottle of soda, singer breaking a glass
speed of sound is dependent on...
wind, conditions, air, temp, humidity, etc. it does not depend on loudness or frequency
