Waves

Waves

1. Waves are disturbances that travel through a medium, carrying energy, sometimes information, but not matter

2. Frequency = f = Hz = the number of vibrations per second of the medium or of the source of the wave.

   • Wavelength = λ = m or other convenient unit = the distance between two successive crests on a transverse wave, or between two successive compressions on a longitudinal wave.
     • Wavespeed = v = m/s = the speed at which an individual crest or trough moves through a medium.
       • eg. sound travels quicker in liquids than gases because the molecules in a liquid are closer together and have stronger forces of attraction between them.
       • Amplitude = a = m or other convenient unit = the height of a wave, measured from the undisturbed (midpoint) position.
         • Time period = T = secs = this is the time taken to produce each complete wave.
           • eg. this is how you would use the equation T = 1÷f
   • eg. 1Hz = I vibration per second etc..

3. Transverse waves = the medium vibrates at right angles to the direction of the energy transfer

   • eg. water ripples
   • Longitudinal waves = the medium vibrates along the same direction as the energy transfer
     • eg. sound waves

4. Wave equation = v = f x λ

   • wave speed = frequency x wavelength

5. ALL waves can refract, reflect and diffract