sound waves Flashcards
state 2 things waves can transfer
energy and information
transverse wave : definition & example
vibrations travel perpendicular to the direction of the wave e.g light, water, and radio waves
longitudinal wave : definition & example
vibrations travel parallel to the direction of the wave e. g sound waves
why cant sound waves travel through a vacuum?
because sound waves need matter to pass on the vibrations
which state do sound waves travel fastest through and why?
solids because there are more particles so its easier to pass on vibrations
pitch definition
depends on how quickly air vibrates, if it vibrates quickly we hear a high pitch sound
what are labels in a wave diagram (5)
wavelength, amplitude, frequency, peak/crest (top of the wave), trough (bottom of the wave)
state the hearing range of a human
20-20,000 Hz
ultrasound definition
a frequency over 20,000Hz
infrasound definition
a frequency below 20Hz
what is compression and refraction?
compression = coils close together
refraction = coils far apart
describe the journey of a sound wave through the ear (4 bullet points)
•sound wave travels into the pinna and down the ear canal, it makes the eardrum vibrate
•vibrations from the eardrum are passed to 3 small bones then to the cochlea
•the cochlea produces signals which are passed to our brain through the auditory nerve
•our brain interprets these signals as sounds
what equation links wave speed, frequency, and wavelength
wave speed = frequency x wavelength
m/s = Hz x m
how do you calculate the frequency?
frequency = number of waves divided by time period
what is the speed of sound in the air?
330 m/s
absorption definition
when energy is transferred from a sound / other wave to a material
amplitude definition
the maximum length of vibrations, measured from the middle of the wave to the peak/trough in metres
auditory range definition
the lowest - highest frequency that an animal can hear
decibel definition
the unit of sound intensity/loudness (dB)
echo definition
reflection of sound waves from a surface back to the listener
which surfaces are good at reflecting sound
hard and smooth surfaces
frequency definition & unit
the number of waves produced per second, unit is Hertz/Hz
medium definition
material that affects light or sound by slowing it down or transferring the wave
oscilloscope definition
device able to view patterns of sound waves that have been turned into electrical signals
