Progressive Waves

• What is displacement in a wave?

  Distance from equilibrium position
• Why is displacement considered a vector quantity?

  It has both magnitude and direction
• What is amplitude in a wave?

  Maximum displacement from equilibrium position
• What is wavelength?

  Distance between points in phase on the wave
• What is a progressive wave?

  A wave that transfers energy without medium transfer
• In what unit is wavelength measured?

  Metres (m)
• What is the period of a wave?

  • Time taken for one complete oscillation
  • Measured in seconds (s)
• What is frequency in the context of waves?

  Number of complete oscillations per unit time
• What unit is frequency measured in?

  Hertz (Hz)

  
• What does the wave equation relate?

  Speed, frequency, and wavelength of a wave

  
• What happens to frequency as wavelength increases?

  Frequency decreases
• What happens to frequency as wavelength decreases?

  Frequency increases
• What is the wave speed denoted by in the wave equation?

  c
• What is phase difference in waves?

  Measure of how much one wave is ahead or behind another
• How can phase difference be determined?

  From the relative position of crests or troughs

  
• What does it mean when waves are in phase?

  Crests or troughs are aligned
• What does it mean when waves are in antiphase?

  Crest of one wave aligns with trough of another
• How is phase difference measured?

  In fractions of a wavelength, degrees, or radians
• What is the phase difference for waves in phase?

  360° or 2π radians

  
• What is the phase difference for waves in antiphase?

  180° or π radians
• What should you remember when labeling wave diagrams?

  • Arrows must reach from crest to crest
  • Arrows for amplitude must go from bottom to top