Waves ( properties of waves ) Flashcards
Topic 2 A & B
what do waves do
transfer energy from one place to another without transferring matter
when do waves happen
when an oscillation travels from the starting point
the direction a wave travels is called
the direction of propagation
when a wave travels through a medium, what do the particles do
they oscillate and transfer energy between each other
when waves transfer energy, do the particles move or don’t ?
they don’t, only the energy is transferred
the amplitude of a wave is
the maximum displacement of a point on the wave from its undisturbed position
the wavelength
is the distance between the same point on two adjacent waves
frequency is
the number of complete waves passing a certain point per second
frequency is measured in
Hz (Hertz)
sign for wavelength
λ
all waves are either (2)
transverse or longitudinal
in transverse waves,
the vibrations are perpendicular to the direction of energy transfer
transverse waves can travel in ( what mediums) when they are mechanical waves
solids and SURFACES of liquids
when electromagnetic wave, transverse waves can travel through
solids, liquids and gases and vacuum
on a transverse wave, the highest point above resit position is called the
crest
in a transverse wave, lowest point below the rest position is called a
trough
most waves are ( transverse or longitudinal)
transverse
longitudinal waves have vibrations that
vibrations that are parallel to the direction of energy transfer
example of longitudinal waves
sound waves, ultrasound
the oscillations of longitudinal waves, oscillate in the ( direction)
the same direction as the direction of wave travel
longitudinal waves move in / through (what meidums)
Move in solids, liquids and gases
can longitudinal waves move through a vacuum
no
wave speed is
the speed at which energy is being transferred
wave equation is ( worded)
wave speed = frequency x wavelength
wave equation in symbol
v = f λ
wave speed is measured in
m /s
wavelength is measured in
metres
wave vibrations for a transverse wave can be shown on a
rope
wave vibrations of a longitudinal wave can be shown on a
spring
key features of a longitudinal wave ( 2)
close together, = compressions
far apart = rarefractions
density of transverse waves does what
stays constant
density of longitudinal waves does what
changes
pressure in transverse waves does what
stays constant
pressure in longitudinal waves does what
changes
the speed of a longitudinal wave is fastest when it moves through a
solid
the speed of a transverse wave is fastest when it travels through
a vacuum
waves are described as
oscillations or vibrations about a fixed point
amplitude is measured in
metres
in a transverse wave, wavelength can be measured from
one peak to the next peak
in a longitudinal wave, wavelength can be measured from
he centre of one compression to the centre of the next
wave period
The time taken for a single wave to pass a point
wavefront is
An imaginary surface representing points of a wave that are at the same point in their cycle
waves with a higher frequency have high/low energy
high
equation relating time period and frequency
FREQUENCY = 1 / Time period
what is the doppler effect
the apparent change in observed wavelength and frequency
the doppler effect can be observed when ?
whenever sources of waves move
how does the frequency change in the doppler effect
changes from high to low as the waves move closer and further
when a stationary object emits waves, the waves spread out ___
systematically
To an observes standing behind an object moving away from them, the waves appear to become
stretched apart because wavelength appears to get longer
(and the frequency appears to get lower)
reflection happens when
waves bounce off a surface
what waves can be reflected
all waves
refraction is when
a wave changes direction when it crosses a boundary between 2 materials at an angle to the normal.
why does refraction happen
because the wave changes speed
how much the wave is refracted depends on ?
and what does that depend on
how much it sped up or slowed down
the density of both materials
what happens to frequency and wavelength in refraction
frequency stays the same
wavelength changes
what waves can be refracted
all waves
