Transverse and Longitudinal Waves

• What do waves do?

  Waves transfer energy from one place to another without transferring matter.
• Explain how waves transfer energy (how they travel from one place to another)

  When waves travel through a medium, the particles of the medium oscillate and transfer energy between each other - the particles stay in the same place, only energy is transferred
• What happens when waves travel from one place to another?

  They oscillate
• On a displacement-distance wave graph, what is the displacement? (what does it mean?)

  The displacement is how far from the equilibrium (the middle line) the wave has oscillated (gone up or down)
• On a displacement-distance wave graph, what is the amplitude? (what does it mean?)

  The maximum displacement
• On a displacement-distance wave graph, what is the trough?

  The lowest point (the very bottom) of an oscillation
• On a displacement-distance wave graph, what is the crest?

  The peak (the highest point) of an oscillation
• On a displacement-distance wave graph, what is the wavelength?

  The distance of one entire oscillation (it has to start from one point on a wave and end at the same point on the next wave e.g. crest to crest)
• On a displacement-distance wave graph, what is the distance? (what does it mean?)


  How far the wave has travelled from its starting point
• On a displacement-time wave graph, what is the time period? (what does it mean?)


  The time it takes for one complete oscillation
• The time period on a displacement-time graph is represented the same way as something else on a displacement-distance graph, what is this something?

  wavelength (time period and wavelength both measure one complete oscillation)
• What is the formula for working out frequency when using a distance-time graph? (referring to frequency and time-period)

  F=1/T frequency (Hz) = 1 / time period (s)
• What is the equation for wave speed (speed of a wave)?

  Wave speed (m/s) = Frequency (Hz) x Wavelength (m)
• What is frequency measured in?

  Hertz (Hz)
• What is wave speed measured in?

  m/s
• What is the difference between transverse and longitudinal waves?

  • Oscillations in a transverse are perpendicular to the direction of energy transfer (direction the wave is moving) - so the vibrations go up and down
  • Oscillations in a longitudinal wave are parallel to the direction of energy transfer (this means that some regions are more spread out than others) - so the waves are vibrating back and forth)
• Most waves we can think of are transverse, give examples of the main ones.

  • All electromagnetic waves
  • Ripples and waves in water
  • Waves in strings (guitar)
• Give an example of a type of longitudinal wave.

  Sound waves