Stationary Waves

• What are standing waves produced by?

  Superposition of two waves
• How are standing waves usually achieved?

  By a travelling wave and its reflection
• What characterizes the wave pattern of stationary waves?

  Peaks and troughs do not move
• How do stationary waves differ from progressive waves in terms of energy?

  Stationary waves store energy

  
• What is the formation of a stationary wave on a stretched spring fixed at one end?

  • A wave travels along the spring
  • Reflects back at the fixed end
  • Superposition creates stationary wave pattern
• What are the two main components of a stationary wave?

  Nodes and antinodes

  
• What are nodes in a stationary wave?

  Regions with no vibration
• What are antinodes in a stationary wave?

  Regions with maximum amplitude
• Do nodes and antinodes move along the string?

  No, they do not move
• In which direction do antinodes move?

  Only in the vertical direction
• What is the phase difference between points on a stationary wave?

  Either in phase or out of phase
• How are points between nodes related in terms of phase?

  They are in phase with each other
• What phase relationship do points with an odd number of nodes between them have?

  They are out of phase
• What phase relationship do points with an even number of nodes between them have?

  They are in phase
• What is the relationship between the length of the string and wavelength in stationary waves?

  • Length \(L\) is related to wavelengths
  • One wavelength \(λ\) is a portion of \(L\)
  • Wavelengths can consist of nodes and antinodes
• What is the definition of a node?

  A point of minimum or no disturbance
• What is the definition of an antinode?

  A point of maximum amplitude
• How are the lengths of strings represented in exam questions regarding stationary waves?

  • Only in whole or half wavelengths
  • Example: 3 nodes and 2 antinodes
  • Example: 2 nodes and 3 antinodes