Waves

• What is a wave?

  A vibration that transfers energy
• What are the two types of waves?

  Transverse and longitudinal waves
• What are the three main properties of waves?

  Wavelength, frequency, and wave speed
• What does the period (T) of a wave represent?

  The time taken for one oscillation
• How do you calculate the frequency of a wave?

  Frequency = wave speed / wavelength
• What is the unit of frequency?

  Hertz (Hz)
• What is the unit of wavelength?

  Metres (m)
• What is the unit of wave speed?

  Metres per second (m/s)
• What is the definition of amplitude?

  Maximum displacement from equilibrium
• How does a transverse wave oscillate?

  Perpendicular to the direction of propagation
• Give an example of a transverse wave.

  Water waves
• How does a longitudinal wave oscillate?

  Parallel to the direction of propagation
• Give an example of a longitudinal wave.

  Sound waves
• What is displacement in a wave?

  Distance from equilibrium position
• What is compression in a longitudinal wave?

  Region of high density
• What is rarefaction in a longitudinal wave?

  Region of low density
• What does polarization refer to in waves?

  Orientation about which it oscillates
• What happens when polarized light passes through a polarizer?

  Only light aligned with the polarizer passes
• What happens to unpolarized light when it passes through a polarizer?

  Intensity decreases by 50%
• How do polarized sunglasses work?

  They block glare from reflected light
• How do 3D glasses create a 3D effect?

  By using two different polarized images
• What is stereoscopic vision?

  Ability to perceive depth using two images
• What are the key features common to all waves?

  • Wavelength
  • Frequency
  • Wave speed
  • Amplitude
  • Period
  • Oscillation
• What are the differences between transverse and longitudinal waves?

  Transverse Waves:

  • Oscillation is perpendicular to propagation
  • Examples: water waves, waves on a string

  
  

  Longitudinal Waves:

  • Oscillation is parallel to propagation
  • Examples: sound waves, compressions in a slinky
• What is the wave equation?

  Wave equation: $v =$$f \cdot \lambda$

  • Where:
  • $v$ = wave speed
  • $f$ = frequency
  • $\lambda$ = wavelength