Diagram of a wave
Some important terms:
- rest position - the undisturbed position of particles or fields when they are not vibrating.
- displacement - the distance and direction from the rest position.
- peak - the highest point above the rest position.
- trough - the lowest point below the rest position.
- amplitude - the maximum displacement of a point of a wave from its rest position.
- wavelength\(\lambda\) - distance covered by a full vibration of the wave, usually measured from peak to peak, or trough to trough. Wavelength is measured in m.
- time period T - the time taken for a full vibration of the wave, usually measured from peak to peak, or trough to trough. Period is a time and so is measured in s. A period of 2 s means that the time for one complete vibration is 2 s or that the time taken for one complete wave to pass a point is 2 s.
- frequency f - the number of waves passing a point each second, or the number of vibrations each second. Frequency is measured in hertz, Hz. A frequency of 50 Hz means there are 50 vibrations every second, or that 50 waves pass a point in one second.