• Standing waves?are produced by the?superposition?of two waves of the same?frequency?and?amplitude?travelling in?opposite directions
• This is usually achieved by a travelling wave and its reflection
  • The superposition produces a wave pattern where the peaks and troughs do not move

   

• Stationary waves?store?energy, unlike progressive waves which?transfer?energy

Formation of a stationary wave on a stretched spring fixed at one end

Comparing Progressive & Stationary Waves

• A stationary wave is made up?nodes?and?antinodes
  • Nodes?are regions where there is no vibration
  • Antinodes?are regions where the vibrations are at their maximum amplitude

   

• The nodes and antinodes?do not?move along the string
  • Nodes are fixed and antinodes only move in the vertical direction

   

• The phase difference between two points on a stationary wave are either?in phase?or out of phase
  • Points between nodes are in phase with each other
  • Points that have an?odd?number of nodes between them are out of phase
  • Points that have an?even?number of nodes between them are in phase

   

• The image below shows the nodes and antinodes on a snapshot of a stationary wave at a point in time

• • Where:
    • L?is the length of the string
    • One wavelength?λ?is only a portion of the length of the string

     

ANSWER:?C

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