Physics- Wave Types + properties + sound and hearing Flashcards
(19 cards)
What is a Wave?
A wave is a repeating, periodic motion resulting in the vibration of particles or changes in electromagnetic fields.
How do particles oscillate in a Transverse wave as opposed to a Longitudinal wave?
In a Transverse wave, the particles oscillate perpendicular to the direction of energy transfer. While in a Longitudinal wave, the particles oscillate parallel to the direction of energy transfer.
What is the wave made up of in Transverse waves as opposed to Longitudinal waves?
In a Transverse wave, the wave is made up of peaks (crests) and troughs.
In a Longitudinal wave, the wave is formed due to varying amounts of pressure between the particles and is made up of an alternating series of compressions and rarefractions.
Give examples of both types of wave:
Transverse wave- water waves, Seismic ‘S’ waves, all electromagnetic waves
Longitudinal wave- sound waves, seismic ‘P’ waves.
What is the Wavelength?
The wavelength (λ) is the distance between corresponding points on adjacent waves. (eg. peak to peak or compression to compression), measured in metres.
What is the Amplitude?
The amplitude (A) is the maximum displacement of the wave from it’s equilibrium position so the distance from the centre to the peak, also measured in metres.
What is the frequency?
The frequency (f) is the number of full oscillations passing a given point in one second, measured in hertz (Hz).
What is the relationship between frequency and wavelength?
Frequency and wavelength are inversely proportional: if you double one value, you halve the other.
A higher frequency equals a ….
higher pitch
A higher amplitude equals a….
louder volume
What is Time Period?
Time period (T) refers to the amount of time from one wave passing to the next, measured in seconds.
What is the equation linking Frequency and Time period?
FREQUENCY = 1 / TIME PERIOD
What is the equation linking Wavelength, Wavespeed and frequency? Be able to rearrange this.
WAVESPEEED = FREQUENCY X WAVELENGTH
Wavespeed - M/s
Frequency - Hz
Wavelength - Metres
How do you present your answer if the frequency value is really high or the wavelength value is really low?
In Standard Form.
Why can’t sounds travel through space?
As sounds require a medium to pass through- they cannot travel through a vacuum, and travel fastest through solids.
What range of Hz can humans hear?
Humans can hear sounds in the range 20 - 20,000 Hz.
Sounds with lower frequencies are…
Sounds with higher frequencies are…
Subsonic
Ultrasonic
Briefly describe the journey of sound waves through our ears:
Sounds are transferred as longitudinal waves, which pass through the air and enter our ears.
-They pass through the ear canal, causing the eardrum to vibrate.
-In turn, the ear bones (hammer, anvil + stirrup) vibrate, agitating the cochlea, where small electrical signals are created, carried to the brain via the auditory nerve.
What may happen to the ear by a sudden loud sound and consistent loud sounds over time.
A sudden loud sound can cause damage to the eardrum or auditory nerve.
Consistent loud sounds over time can cause damage to the delicate hair cells on the cochlea, so messages can’t be sent to the brain as well as before.
