sound waves, ultrasound and seismic waves
- Created by: rxbyw
- Created on: 11-04-19 16:32
a sound wave is a longitudinal wave caused by vibrating particles
sound travels faster in solids than in liquids and faster in liquids than in gases
sound waves refract when they enter different materials
when a sound wave enters a denser medium its speed and wavelength increases but the frequency stays the same
when a sound wave meets a solid object the air particles hitting the object causes the particles in the solid to vibrate
the vibrating particles hit the next particles and causes a series of vibrations that passes the sound wave through the object
sound waves of frequency 20Hz to 20kHz causes air in the ear to vibrate which causes your ear drum to vibrate
these vibrations are passed on to tiny bones in the ear called ossicles though the semicircular canals and to the cochlea
the cochlea turns the vibrations into electrical signals which get sent to the brain and allows you to hear
humans can only hear sounds with frequencies from 20 Hz to 20 kHz because the ear drum and other parts in the ear can only vibrate at certain frequencies due to their structure.
ultrasound:
ultrasound waves are sound waves with frequencies greatet than 20 kHz
it cannot be heard by people as it is outside the normal range of human hearing
properties:
ultrasound gets partially reflected
partial reflection is when waves are incident on a boundary some are reflected and some are transmitted
the reflected waves are known as echos
exploring structures with ultrasound:
partial reflection means that ultrasound has useful applications
it can be involved in imaging or locating objects that we cannot see
medical imaging:
this is used to see inside the body which allows doctors to diagnose medical conditions and check the bodys function
ultrasound is used in…
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