Wave speed (m/s) = Frequency (Hz) x Wavelength (m)
Diffraction
To increase diffraction, decrease
the gap or increase the
wavelength
Waves diffract when they go
through a gap that is larger than
their wavelength
The most diffraction happens when the
gap is the same size as the wave
Refraction
Waves refract because when
they enter a medium they
change speed
Waves slow down
entering the medium and
speed up exiting it
Types of waves
Transverse
Electromagnetic waves
Longitudinal
Sound waves
Seismic Waves
Reflection
Angle of incidence = Angle of reflection
The normal is an imaginary line
perpendicular to the surface
Uses of waves
Infrared
TV Remotes
Optical Cables
Visible Light
Optical Cables
Camera
The aperture determines the amount of light let in
The shutter time determines how
long the sensor/film is exposed to
the light
Microwaves
Satellites
TV
GPS
Phone
Can go through the cloud and
water vapour layer in the atmosphere
Radio Waves
Transverse
Short length radio
waves reflect off
the ionosphere and
the earth.
Short length radio waves do not work around hills
and valleys as the wave has to directly reach the
receiver as it can not go far through buildings or
land masses
Long radio waves diffract around
the earth and so are not blocked by
landmasses such as hills or valleys
Electromagnetic Spectrum
Radio Waves
Microwaves
Infrared
Visible Light
Ultra violet
X-Ray
Gamma Ray
Frequency increases along the spectrum and so wavelength decreases
Doppler Effect
Observed frequency of wave
increases as object moves
towards you so the sound
seem higher
Observed frequency of
wave decreases as object
moves away from you so
the sound seems lower
As galaxies move
further away from us
they shift towards the
red end of the
spectrum
Origin of the Universe
The Big Bang Theory
Everything as we know it was
compressed into the tiniest space
imaginable and then it exploded
This isn't quite right because the
rate of expansion should be
slowing down but it's speeding up
Cosmic Background Microwave Radiation
This is proof for The Big Bang Theory
Everything is cooling down after the
expansion and so the frequency of the
radiation is now given off as microwaves
Steady State Theory
The theory that everything was
always here and will always
continue to be
The major flaw is expansion
Matter cannot be created so
how then can the universe
be expanding?