Waves

• What is a progressive wave?

  A wave that transfers energy without material
• How do water waves behave?

  Water particles move up and down
• What is amplitude in a wave?

  Maximum displacement from equilibrium
• What is the unit of frequency?

  Hertz (Hz)
• What does wavelength represent?

  Length of one whole oscillation
• What is the unit of wavelength?

  Meter (m)
• How is wave speed calculated?

  Speed equals frequency multiplied by wavelength
• What is the unit of wave speed?

  Meters per second (m/s)
• What does phase indicate in a wave?

  Position of a point on a wave cycle
• What is the unit of phase difference?

  Radians, degrees, or fractions of a cycle
• When are two points on a wave in phase?

  When they have the same displacement and velocity
• What is the condition for two points to be completely out of phase?

  They are an odd integer of half cycles apart
• What is the formula for wave speed?

  $c =$$f \lambda$
• What is the formula for frequency?

  $f =$$\frac{1}{T}$
• What defines transverse waves?

  Oscillation at right angles to energy transfer
• What type of waves are all electromagnetic waves?

  Transverse waves
• How can transverse waves be demonstrated?

  By shaking a slinky vertically
• What characterizes longitudinal waves?

  Oscillation parallel to energy transfer
• What is a polarized wave?

  A wave oscillating in only one plane
• Why can only transverse waves be polarized?

  Because their oscillations are perpendicular to travel
• What is the function of Polaroid sunglasses?

  They reduce glare by blocking polarized light
• How do TV and radio signals utilize polarization?

  They are plane-polarized by transmitting aerials
• What is superposition in wave theory?

  Combination of displacements of two waves

  
• What is constructive interference?

  When two waves have displacement in the same direction
• What is destructive interference?

  When one wave has positive and another negative displacement
• What is a stationary wave?

  A wave formed from two progressive waves superimposing

  
• What happens at antinodes in a stationary wave?

  Regions of maximum amplitude are formed
• What happens at nodes in a stationary wave?

  Regions of no displacement are formed
• How is a stationary wave formed on a string?

  By superposition of waves traveling in opposite directions
• What is the first harmonic?

  The lowest frequency at which a stationary wave forms
• How is the distance between adjacent nodes related to wavelength?

  It is half a wavelength
• What is the formula for calculating frequency of a stationary wave?

  $f =$$\frac{1}{2L} \sqrt{\frac{T}{\mu}}$
• How do you find the second harmonic frequency?

  Double the first harmonic frequency
• How do you find the third harmonic frequency?

  Triple the first harmonic frequency
• How can stationary sound waves be demonstrated?

  By placing a speaker in a closed tube
• What is path difference in wave interference?

  Difference in distance traveled by two waves
• What characterizes a coherent light source?

  Same frequency, wavelength, and fixed phase difference
• What is Young's double slit experiment used to demonstrate?

  Interference of light from two sources

  
• What happens when light passes through two slits in Young's experiment?

  It creates a pattern of light and dark fringes

  
• What is the formula for fringe spacing in Young's experiment?

  $w =$$\frac{s \lambda}{D}$