Waves

• What do waves transfer from one place to another?

  Energy
• How do particles in a wave move?

  They oscillate about a particular point
• What can happen to waves when they encounter different media?

  They can be reflected and refracted
• What type of waves require particles to propagate?

  Mechanical waves
• Can electromagnetic waves propagate in a vacuum?

  Yes, they can
• In longitudinal waves, how do particles oscillate?

  Parallel to the direction of energy transfer
• Through which states of matter can longitudinal waves travel?

  Solids, liquids, and gases
• In transverse waves, how do particles oscillate?

  Perpendicular to the direction of energy transfer
• Through which states of matter can transverse waves travel?

  Only through solids
• What is the definition of wavelength?

  • Distance between two neighboring wave points
  • Measured from crest to crest or trough to trough
• What is amplitude in wave terms?

  Maximum displacement from rest position
• What is the unit of frequency?

  Hertz (Hz)
• How many waves per second equals 1 Hertz?

  1 wave per second
• What is the relationship between kilohertz and hertz?

  1 kHz = 1000 Hz
• What is the relationship between megahertz and hertz?

  1 MHz = 1,000,000 Hz
• What is the wave equation?

  Wavespeed = frequency x wavelength
• What are the units for wavespeed?

  Metres per second (m/s)
• What is the formula for the time period?

  T = 1/frequency
• How can you find the wavespeed using a ripple tank?

  Count waves in 10 seconds, divide by 10
• What is a problem when measuring wavespeed in a ripple tank?

  Waves are moving, hard to judge position
• What is a solution to the problem of measuring wavespeed?

  Use a projection to judge wave position
• How can you accurately measure wavelength in a ripple tank?

  Take a picture to get a still image
• What is the speed of all electromagnetic waves in a vacuum?

  300,000,000 m/s
• What do all electromagnetic waves do to temperature?

  They raise the temperature
• What do electromagnetic waves transfer from place to place?

  Energy
• What can electromagnetic waves do when they encounter materials?

  They can be reflected, refracted, and diffracted
• What happens to frequency when wavelength decreases?

  Frequency increases
• What is the order of the electromagnetic spectrum from low frequency to high frequency?

  • Radio
  • Microwaves
  • Infra-red
  • Visible Light
  • Ultra-violet
  • X-ray
  • Gamma
• What is the order of the electromagnetic spectrum from short wavelength to long wavelength?

  • Gamma
  • X-ray
  • Ultra-violet
  • Visible Light
  • Infra-red
  • Microwaves
  • Radio
• Why do electromagnetic waves have different properties and uses?

  Due to their different wavelengths and frequencies
• What is the equation used to calculate wavelength or frequency?

  Speed = wavelength x frequency
• What happens to the energy of electromagnetic waves as their frequency increases?

  The energy increases
• What can the human eye detect in the electromagnetic spectrum?

  Visible light
• What other parts of the electromagnetic spectrum can affect our bodies?

  X-rays, gamma rays, ultra-violet
• What can microwaves and radio waves do to body tissue?

  They can heat body tissue
• What is a potential hazard of gamma rays?

  They can damage the retina
• What is a potential hazard of UV rays?

  They can cause sunburn and cancer
• What is a potential hazard of X-rays?

  They can cause ionization
• What are the uses of different electromagnetic waves?

  • Radio waves: television, radio
  • Microwaves: mobile phones, satellite TV, cooking
  • Infrared: remote controls, heaters, cooking
  • Visible light: photography
  • UV: energy-efficient lamps, tanning
  • X-rays: medical imaging
  • Gamma rays: medical treatments
• What is the common speed of all members of the electromagnetic spectrum?

  Speed of light