P1 A spectrum of waves

P1 A spectrum of waves

1. Wave properties

   • The amplitude of a wave is the maximum displacement of a particle from its rest postiion
   • The crest of a wave is the highest point on a wave above its rest position
   • The trough of a wave is the lowest point on a wave below its rest position
   • The wavelength of a wave is the distance between who successive points on a wave having the same displacement and moving in the same direction
   • The frequency of a wave is the number of complete waves passing a point in one second
   • Wave speed = frequency x wavelength

2. Getting messages across

   • Some optical instruments use two or more plane mirrors
   • Refraction occurs because the speed of waves decreases as the wave enters a more dense medium and increases as the wave enters a less dense medium. The frequency stays the same but the wavelength changes
   • Diffraction is the spreading out of a wave as it passes through a gap.
   • The size of a communications receiver depends on the wavelength of the radiation