• Waves are generated by?oscillating sources
  • These oscillations travel?away?from the source

   

• Oscillations can propagate through a?medium?(e.g. air, water) or in a?vacuum?(i.e. no particles), depending on the wave type

Wave Features

• In order to describe the properties of travelling waves, the following keywords need to be defined:
  • Wavelength?λ?(m) is the distance between a point on a wave and the same point on the next cycle of the wave, e.g. two crests, or two troughs
  • Amplitude?A?(m) is the magnitude of the maximum displacement reached by an oscillation in the wave
  • Period?T?(s) is the time taken for one complete oscillation at one point on the wave
  • Frequency?f?(Hz) is the number of complete wave cycles per second
  • Wave speed?c?(m s-1) is the rate of movement of the wave

Diagram showing the amplitude and wavelength of a transverse wave

• The frequency?f?and the period?T?of a travelling wave are related to each other by the equation

(i) Identify the amplitude?A?of the wave on the graph

• • The amplitude is defined as the maximum displacement from the equilibrium position (x?= 0)

• • The amplitude must be converted from centimetres (cm) into metres (m)

A = 0.1 m

(ii) Calculate the frequency of the wave

Step 1: Identify the period?T?of the wave on the graph

• • The period is defined as the time taken for one complete oscillation to occur

• • The period must be converted from milliseconds (ms) into seconds (s)

T?= 1 × 10–3?s

Step 2: Write down the relationship between the frequency?f?and the period?T

Step 3: Substitute the value of the period determined in Step 1

f?= 1000 Hz