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