waves

• radiowaves.

  longest wavelength

  lowest frequency

  long wave-transmitted huge distance(good for long range communication)

  short wave-long distance(e.g:TV,FM,radio)
• what can long waves do?

  travel long distances

  bend around the curved surface of the earth!
• how do microwaves work?(micro wave ovens)

  -waves that are absorbed by water molecules

  the energy from the waves gets absorbed by all the molecules

  the molecules vibrate more

  transfer energy to neighbouring molecules

  spreads throughout the food via conduction and convection
• what are microwaves that aren't absorbed by water molecules

  used for satellites

  pass through the atmosphere
• microwaves and infrared are what in high quantities?

  harmful
• what does infrared work?

  emitted from all objects that have a thermal energy(depending on the object's temperature)
• what are infrared waves used for?

  cooking

  electric heaters

  infrared camera

  spot living organisms
• how does an electric heater work?

  use electrical energy to heat the metal of the heater,because it is so hot

  it emits infrared radiation to the surroundings,which hear our room
• how infrared cameras work to find animals?

  animals are warmer than the surrounding environment

  therefore emit more infrared can detect the infrared radiation
• what are the properties of x rays?

  shortest wavelength

  highest frequencies
• what do x rays absorb?

  dense materials

  pass straight through parts that are mostly air!
• what must be worn when dealing with x ray?

  lead aprons
• who is most in danger when using x rays?

  staff
• uses of x rays?

  view the internals structure of objects

  detect broken bones/other diseases
• what are the uses of gamma rays?

  medical imaging+radio therapy

  gamma rays can kill micro-organisms without causing other damage
• gamma rays with food?

  -fresh for longer,share to eat!

  -kill all the harmful micro-orbes without altering the food

  -gamma rays can kill micro-organisms without causing any other damage
• what are the uses of visible light?

  -communication(optical fibres)

  -transmit data really quickly,for long distance
• advantages of x rays?

  cheap and quick

  gives the patient a small amount of radiation
• advantages of x rays?

  cheap and quick

  gives the patient a small amount of radiation
• properties of UV light?

  shorter wavelength than visible light
• what is UV light used for?

  sun tans

  sun beds

  florescence
• what are colour filters used for?

  used to filer out the particular colours

  -by transmitting certain wave lengths of light,while absorbing the rest
• what colour has the longest wavelength?

  red
• what has the shortest wavelength?

  violet
• what colours are in the spectrum?

  Red

  Orange

  Yellow

  Green

  Blue

  Indigo

  Violet

  ROYGBIV
• why is white not apart of the spectrum?

  white is a combination of all the wavelengthd
• why is black not apart of the spectrum?

  black is an absence of light
• the object appear the colour they do:

  due to the wavelengths of light hitting it

  properties of the object

  determines which objects are absorbed,reflected or transmitted
• does opaque material transmit light?


  no
• what happens to objects wave-length or light?

  absorbed
• what will happen to an object with a range of wavelengths?


  reflected
• what are the primary colours of light?

  Red, green, blue
• what is transparent light

  transmits nearly all the light(glass in a window)
• what is a translucent light??

  only transmits some of the light
• what is the colour determined on?


  Wavelength
• wavelength of the primary colours can be..

  added together to make that colour
• what colours do primary colour filters let through?

  three primary colours

  the same colour as the filter
• how do x rays work

  1)x rays are fired at the patient

  2)x rays are absorbed by materials which are very dense,like bones

  3)x rays transmited through materials which are not very dense like lungs and intestines

  4)x rays that pass through are detected by a detector plate to make an x ray image
• how do lenses work?

  convex:refract parallel rays of light,inwards to a single point(principle focus)

  concave:cause them to refract parallel rays of light outwards

  shorter the focal length,more powerful the lens,refracts light more strongly
• how are images formed?

  images are formed at points,where all the light rays from a particular point on an object,appear to come together