Waves Flashcards
What do waves transfer
Energy
Transverse waves
A wave where the vibrations are right angles to the direction of travel
Longitudinal wave
A wave where the vibrations are along the same direction as the direction traveled
Examples of transverse waves
Water waves
Electromagnetic radiation
When does defraction occur
When waves pass through a gap or around an objects
Electromagnetic radiation speed?
Travels at the speed of light 3.0 * 108
Refraction occurs when ?
When waves pass from one medium to another
What can waves be mad of
Vibrations
Oscillations of particles
Feilds
Examples of longitudinal waves
Sound waves
Wavelength
Length of one full wave
Amplitude
Hight of wave
Represents energy
Speed
Distance travelled per unit time
Period
Time it takes 1 wave to pass a point
Frequency
Number of waves produced per second
Wave speed
The distance by a wave per unit time
When is the defraction effect greatest
The longer the wavelegth
If the size of the gap same as the wavelegth
When are waves slightly defracted
If the size of the gap is much larger than the wavelength
Why is it easier to receive radio waves on a hill
Radia waves are longer which means they diffract more
Sources of :
Radio waves
Microwaves
Infra red radiation
Visible light
Ultra violet
X - ray
Gamma ray
Radio mast
Magnetron
Hot objects
LED’s
The sun
Collision between high energy objects and a metal target
Radioactive substances
Detectors of :
Radio waves
Microwaves
Infra red
Visible light
Ultra violet
X - ray
Gamma ray
Aerial
Water
Thermistor CCD’s
Retina
Fluorescent materials
Photographic film
Geiger Muller tube
Use of :
Radio waves
Microwaves
Infrared
Visible
Ultra violet
X ray
Gammma ray
Radio telescope
Mobile phones
Remote controls
Lasers
Security marking
Medical sans
Radio therapy
What does wave speed demand on
The medium which it travels through
When does light slow down
When it enters a more ense medium
Different mediums cause light to Chang direction
Where is the normal of an object
90 degrees to the object
What happens when wavelength increases
Frequency decreases
Indirectly porportional
What does diffraction not effect
Wavelength and frequency
What part of the body detect infrared
The skin
What does sun screen do
Blocks the ultraviolet from the sun
O-zone layer
Stops too much ultra violet getting to the skin
X-ray through soft and dense tissues
X-ray passes through soft tissues such as skin and muscle
X-ray absorbed by dense tissues such as bones
What don’t gamma rays not affect gamma ray sensors
Gamma rays only effect living tissues
High frequency waves
Travel in straight lines and don’t follow the cuviture of earth
Uses or refraction of light
Telescope
Microscope
Why does white light through a prism causes visible light
White light is made up of different coloured.
Colours have different frequency
Refraction
Wave changes speed when it moves from one medium to another
Defraction
When waves
- pass a barrier
- edge
- through a gap
It bends around it
Pensi in water
Light from air immersed object has to cross the water
This cause ray of light to change direction
When does light ben towards the normal
When it goes from less to dense to more dense
When does light bend away from the normal
More dense ——> less dense
