Waves

• What do waves transfer and in what direction?

  Waves Transfer Energy in the direction they are travelling
• What do waves do when travelling through a medium?

  The particles of the medium oscillate and transfer energy between each other.
• What is the amplitude of a wave?

  The maximum displacement of a point on the wave from its undisturbed position.
• What is the Wavelength?

  The distance between the same point on two adjacent waves.
• What is the frequency?

  The number of complete waves passing a certain point per second
• What is the frequency measured in?

  Hertz
• What is the equation of Period?

  T=1/f
• What is Period measured in?

  Seconds
• What are transverse waves?

  Waves that oscillate perpendicular to the direction of energy transfer.
• Transverse waves have sideways vibrations
• Name some examples of transverse waves?

  ripples on a waters surface , all electromagnetic waves
• What are longitudinal waves?

  Waves that oscillate parallel to the direction of energy transfer
• What are some examples of longitudinal waves?

  Sound waves in air
• Longitudinal waves show areas of compression and rarefaction.
• What is the equation for wave speed?

  Wave speed=Frequency x Wavelength
• What are electromagnetic waves?

  Electromagnetic waves are transverse waves that transfer energy from the source of the waves to an absorber.
• How are the electromagnetic waves grouped?

  in terms of their wavelength and their frequency. Going from long to short wavelength (or from low to high frequency)
• What part of the spectrum do we see?

  Visible light
• Where do EM waves travel at the same speed?

  Air or a vacuum
• What is Period?


  The time for one wave to pass a point
• Do electromagnetic waves need a medium to travel in?

  No
• What do different materials do to EM waves?

  Absorb , Transmit , reflect
• Waves can change direction when they change speed. moving from one medium to another
• What are radio waves used for?

  To transmit radio and terrestrial TV signals
• Why are radio waves used?

  Because they can travel long distances before being absorbed
• Radio waves can reflect off a layer off charged particles in the atmosphere (ionosphere)
• Microwaves are used for heating foods
• Why are microwaves used to heat food?

  This is because most food contain a lot of water particles and water molecules absorb the energy of microwaves. The energy causes the temperature to increase
• What are microwaves used for ?

  To heat food and to communicate with satellites in space
• Why are microwaves used in space?

  Because microwaves can be passed through the earths atmosphere without reflected or refracted.
• What are infrared radiation used for ?

  electrical heaters, cooking food, infrared cameras
• What is the process behind infrared radiation ?

  The energy of infrared is easily absorbed by the surface of the object
• What Is the use of visible light?

  fibre optic communications
• What are Ultraviolet waves used for ?

  energy efficient lamps, sun tanning
• Where is Ultra violet light created in an energy efficient bulb?

  In the bulb
• Why does Ultra violet waves carry more energy than visible light?

  Because it has a shorter wavelength
• What are Optical fibres?

  Very thin strands for glass
• Why can fibre optics carry a lot of information?

  Because visible light have a short wavelength
• What are X-rays and gamma rays used for?

  medical imaging and treatments.
• Explain how the properties of X-rays make them suitable for the medical imaging of bones.

  pass through soft tissue

  (but) absorbed by bone