Waves

• What does a wave transfer?

  Energy
• What causes a wave?

  Vibration
• What is a transverse wave?


  Vibration is at a right angle (up and down) compared to the direction of the wave
• What is a longitudinal wave?

  Vibration is parallel (side to side) compared to the direction of the wave
• What is a compression?

  Where particles in a longitudinal wave are closest together
• What is a rarefaction?


  Where partices in a longitudinal wave are furthest apart
• What is the amplitude of a wave?

  Distance from the middle of a wave to the top or bottom
• What is a wavelength?


  Distance from one point of a wave to the same point on the next wave
• What is frequency?


  The number of waves that go past a point in a second
• What is the wave=speed equation?

  Wave-speed = frequency x wavelength
• What speed do EM waves travel?

  300, 000, 000 m/s (300 million m/s)
• What speed does sound travel at?

  330 m/s
• Name the four things that may happen when light strikes a material?

  • Transmission
  • Reflection
  • Refraction
  • Absorption
• What is the law of reflection?

  Angle of incidence = angle of reflection
• What is refraction?


  When wave bends because it enters a medium with a different density)
• List the 7 EM waves in order of longest to shortest wavelength

  • Radio
  • Microwave
  • Infrared
  • Visible light
  • Ultraviolet
  • X-rays
  • Gamma rays
• Which EM wave has the most frequency?

  Gamma
• Which EM wave has the highest energy?

  Gamma
• Which three EM waves are ionising?

  Gamma, X-ray and UV
• What are radio waves used for?

  Television and radio
• What are microwaves used for?

  Satellite communication, cooking food
• What are infrared waves used for?

  Heating, cooking food, infrared cameras
• What is visible light used for?

  Fibre optic communication
• What are ultraviolet waves used for?

  Sunbed, energy efficient lamps
• What are X-rays and gamma rays used for?

  Medical imaging and treatments