waves Flashcards
define amplitude
the maximum displacment of the wave
how do waves travel?
through oscilation (vibration)
define wavelength
the distance of an entire oscilation
define a timeperiod
the time it takes for one complete oscillation
define frequency
number of complete oscillations per second
define a transversal wave
give an example
oscillations are perpendicular (to the direction of energy transfer)
electromagnetic
define a longtitudinal wave
give an example
oscillations are parallel to the direction of energy transfer.
(some waves are more compressed and some are more spreadout)
sound wave
define absoprtion
the waves energy is transferred to the material
define refraction
waves bend through a material and come out at a different angle
define reflection
the wave is bounced off of the material
define transmission
a wave enters a material but carries on travelling - often leads to refraction
define specular reflection
why?
all incoming light waves will be reflected in the same direction
as all the normals are the same
define diffuse reflection
why?
light rays are reflected in different directions
as the normals are different
why do waves travel at different speeds in different mediums?
due to different densities
e.g away/ towards the normal
if an angle is refracted in a more dense medium, which direction will it change to?
towards the normal
if a wave is refracted into a less dense medium will it travel towards or away from the normal?
away as it speeds up
what type of waves are electromagnetic waves?
transversal
what are the 3 types of radiowave?
what are radiowaves used for?
how are they made?
long
short
very short
communication
through alternating current
what are the 2 types of microwaves?
give uses for both
those absorbed by water - microwave oven
not absorbed by water -communication
What emits infared radiation?
give 2 usues of IR
all things that emit thermal heat
cooking
heating a room etc
What can visible light be used for?
how is it transported?
communication
through optic fibres, reflecting the waves through the wire
what are some uses of UV radiation?
light bulb
security
sterilising water
What are 3 uses of gamma rays?
why are gamma rays useful in sterilisation?
medical imaging
to treat cancer (radiotherapy)
sterilisation
as they can kill micro-organisms without causing any other damage
what is an opaque object?
an object which does not transmit light
all wavelengths of light are absorbed or reflected
