Waves in matter 〰
Wave motion
Wavelength
Frequency
Amplitude
Period
time for 1 oscillation to occur (s)
Types of Waves
Longitudinal
Transverse
number of waves in one second (hertz)
T=1/f
f=1/t
Plate Boundaries
Conservative
Destructive
distance between each wave
Collision Zone
Constructive
wave length= v/f
Height of the crest from the centre
When the two plates are forced into each other.
Wave velocity
The speed of the waves (m/s)
V = f x wavelength
When one plate boundary is forced under the other.
When two plates move away from each other and the space is filled with magma that rises up through the gap and over onto the top to create a new rock crust.
Fold mountains
Metamorphism
P waves
S waves
medium moves parallel to wave direction
This leads to violent volcanoes with low viscous magma
Medium moves perpendicular to wave direction
When the plates move in opposite directions or in the same direction but at different speeds.
Sound waves as they form waves that have compressions
Waves in water as they form visible waves with a peak and a trough
Sound needs a medium to travel as it is a longitudinal wave which requires a medium
Waves at a material interface
The human ear
A sound wave is produced by an object
The sound wave travels through the air
The ear flap (pinna) funnels the sound into the ear
Ear drum vibrates
Three small bones pass the vibrations on to the cochlea and amplify them
Nerve cells in the cochlea send messages to the brain when moved by vibration
Nerve carries message to brain
Ultrasound
In the body
In the water
Ultrasound is sent into the body
Ultrasound wave is sent out from the ship
When it hits the sea floor it is reflected back
Distance to sea floor is calculated
1/2 x speed x time
Reflected off organs and components of the body
Processed by machine
Cannot travel through a liquid
Slow
Can travel through both liquid and solid
Fast
When waves hit a material interface several things happen
There is a reflection
The wave changes direction
The wave slows down
Surface
Longer wave
Slow speed
Large amiitude
How do scientists calculate the centre of the earth
Earthquakes
Complex calculations using the P and S waves
P waves can travel through the liquid core
S waves cannot travel through liquid core
No waves are detected directly underneath the core
Tells scientist how wide the core is
Waves are distorted and change direction when they pass through the core