What you must understand!
- There two types of waves: longitudinal and transverse waves.
- Both waves only transfer energy from one point to another without physically transferring the medium the wave travels in.
- The source of a wave is a vibration or an oscillation.
- Points that are considered to be in phase must meet 3 criteria:
- They must have the same direction of motion
- They must have the same speed
- They must have the same displacement from their rest position
- Wavefront is an imaginary line on a wave that joins all adjacent points that are in phase.
Deduction of wavelength and period from displacement-distance and displacement-time graphs
We can deduce amplitudes of the waves from both graphs. However, the graph on the left will allow us to deduce the period of the wave (displacement-time) whereas the one on the right will only provide us with the wave length (displacement-distance).
Visualisation of Particles Movement in Longitudinal Waves In a Medium (air)
- Particles only oscillate back and forth about their individual equilibrium positions.
Visualisation of Particles Movement in a Rope Generating Transverse Wave
- Particles only oscillate up and down about their individual equilibrium positions.
Visualisation of Particles Movement in Water Wave
- In real life, water wave like the one below is a combination of both transverse and longitudinal motions.