Waves Revision

Waves Revision

1. Types

   • Progressive
     • Carry energy of oscillation through a medium. If they are mechanical and through space, they are electromagnetic waves.
   • Transverse
     • Progressive waves whose displacements are at right angles to the direction of energy flow
   • Longitudinal
     • Progressive Waves whose displacements are along the line of energy flow. e.g. sound waves

2. Properties

   • Frequency, f, Hz
     • The number of oscillations per second or the number of waves that pass a point per second.
   • Period, T, s
     • Time taken for 1 complete oscillation T=1/f= 2π/ω
   • Phase, Ø, rad
     • angle in radians, between 0 and 2π which indicates a fraction of a cycle completed
   • Wavelength, λ, m
     • distance in m between two adjacent peaks
   • Amplitude, A, m
     • the maximum displacement of the wave from the rest position (equilibrium). Measure of the energy of the wave.
   • Angular Velocity, rads-1, ω Rate of change of angular direction of a radius joining a point on a rigid body to the axis about which it is rotating. ω = θ/t = 2π/T Phase change each seconde.g. 1 cycle/sec = 2πrads-1
   • V=fλ