Sound And Ultra Sound Flashcards
What type of waves are sound waves?
Longitudinal waves
Why can’t sound travel through a vacuum?
Because there are no particles to carry the vibrations.
Where does sound enter in the ear and then what does it make vibrate?
It enters the ear canal and then makes the ear drum vibrate.
What happens after the ear drums vibrated?
Three small bones transmit these vibrations to the cochlea, these produce electrical signals which pass through the auditory nerve to the brain. This is where they are interpreted as sound.
What is the pitch of a noise related to?
The frequency of the wave
How is the amplitudes related to the sound?
It’s related to the volume. High amplitude sound waves are loud.
Why can humans only hear a limited range of frequencies?
Because the cochlea is only stimulated by a limited range of frequencies.
What is the range of human hearing?
20 hz-20,000 hz
What are sound waves below 20 hz called?
Infra sound
What are waves called with a higher frequency of 20,000 Hz.
Ultra sound
Why is ultrasound used for?
Breaking kidney stones
Cleaning jewellery
Foetal scanning
Detecting cracks in machinery
How do you calculate the depth of a crack lot wear a baby might be using ultrasound and how may we calculate this?
Depth=velocity*time
When ultrasound waves are reflected at a boundary we know something is there and can calculate the time it took to get there and back to create an image for our selves.
How can we calculate where objects are in deep water using high frequency sound waves?
The timer between a pulse of sound being transmitted and detected and the speed of sound in water can be used to tell us where the reflecting surface or object is.
What do earth quakes produce?
Seismic waves
What are S waves and what can they do?
S waves can only travel through solids and cannot be detected on the other side of the earth, this suggest that the mantle has solid properties but the outer core must be liquid.
