sound waves Flashcards
what is the definition of a wave
- a disturbance that travels through a medium
- carry energy
what are the 4 characteristics of a wave
- how they propagate
- amplitude
- frequency
- wavelength
what are the 2 types of propagation waves
- transverse waves
- longitudinal waves
what is a transverse wave
- propogates perpendicular to its meidum
what is the highest peak of the wave called
crest
what is the lowest valley called
trough
what is a longitudinal wave
- propagates parallel to it’s medium
what is it called when particles are close together in a longitudinal wave
compression region
what is it called when particles are far apart in a longitudinal wave
rarefaction region
what is the definition of an amplitude of a wave
maximum distance travelled by particles in the medium compared to its position at calm
how do u measure amplitude for a transverse wave
position at calms to maximum crest or position at calm to lowest trough
how do u measure amplitude for longitudinal waves
- measure the length of the are of compression
- higher the compression = higher the amplitude
what is wavelength
length of waves complete cycle
what is frequency
number of cycles per unit of time
measures in hertz Hz
- number of hertz = number of cycles completed in 1 sec
what is the scale of hertz that humans can hear
20hz-20000hz
what is an infrasound
sound less than 20hz
what is an ultrasound
sound more than 20000hz
what are the two types of waves
- mechanical
- electromagnetic
what is a mechanical wave
- waves that require a medium to move
- cause a disturbance that changes the medium
what is an example of a mechanical wave
sound waves
what are mediums
solid
liquid
gas
what is an electromagnetic wave
- travel in medium and vacuum
what is an example of an electromagnetic wave
radio waves, light waves
what are the characteristics of a sound wave
- longitudinal wave
- mechanical wave
- can move through solids, liquids. gases
what is the process of a sound wave being created
- disturbance is caused in the environment
- disturbance is then passed on to the surrounding medium
- then the wave transmits energy
what does the speed of sound depend on
- depends on the medium which the sound is travelling through
- more matter = FASTER
what medium does sound travel the fastest through
solids because they have the most matter
what is the decibel scale
- represents the intensity of sound by the human ear
- symbol is Db
- intensity is referring to how much energy the wave is carrying
- the scale goes by 10x
how much louder is 50 dB from 20dB
1000X louder
what is the maximum dB that humans should not listen to
sounds over 100db
