wave behaviour

• What is amplitude in a wave?


  The distance from undisturbed position to peak
• What is wavelength in a wave?

  The distance between two identical points
• How is wavelength measured in a transverse wave?

  From one peak to the next peak
• How is wavelength measured in a longitudinal wave?

  From center of one compression to next
• What is frequency in wave terms?

  The number of waves passing a point per second
• What is the time period of a wave?

  The time taken for a single wave to pass
• How is frequency calculated from time period?

  Frequency = 1 / time period
• How is wave speed calculated?

  Wave speed = frequency x wavelength
• What happens to wave speed when frequency increases?

  Wave speed increases
• What happens to wave speed when wavelength increases?

  Wave speed increases
• How is time period related to frequency?

  Time period is inversely proportional to frequency
• What are the characteristics of transverse waves?

  • Have peaks and troughs
  • Vibrations are perpendicular to energy transfer
  • Examples: light, electromagnetic waves, water ripples
  • Can move in solids and liquid surfaces, not in gases
  • Electromagnetic waves can move in solids, liquids, gases, and vacuum
• What are the characteristics of longitudinal waves?

  • Have compressions and rarefactions
  • Vibrations are parallel to energy transfer
  • Example: sound waves
  • Transfer energy, not particles of the medium
  • Can move in solids, liquids, and gases, but not in vacuum
• How does the density of a medium affect sound wave speed?

  Sound travels fastest in solids
• What changes occur when sound waves move from one medium to another?

  Changes in wave speed, frequency, and wavelength
• What is refraction in sound waves?

  Change in velocity causing change of direction
• What happens to sound waves moving from a denser to a less dense medium?

  Wavelength decreases, frequency stays the same
• What happens to sound waves moving from a less dense to a denser medium?

  Wavelength increases, frequency stays the same
• How does temperature affect the speed of sound in air?

  Speed increases on warm days
• What happens to sound waves in the human ear?

  They are transferred from air to solid components
• What are the two main solid components of the human ear?

  The eardrum and three small bones
• How does the eardrum respond to sound waves?

  It vibrates due to pressure variations
• What is the role of the cochlea in hearing?

  Detects sound and sends messages to the brain
• What is the range of frequencies a human can hear?

  20 Hz to 20,000 Hz
• How does aging affect human hearing?

  Reduces ability to hear high frequencies
• What happens to the cochlea's hairs as a person ages?

  Shorter hairs stop responding to high frequencies
• What is the method for measuring wave properties in a ripple tank experiment?

  1. Set up apparatus and fill tank with water (1 cm deep)
  2. Turn on power supply and light source
  3. Measure wavelength using a ruler and wavefronts
  4. Determine frequency by timing waves passing a point
  5. Record frequency and wavelength, repeat measurements
• What can happen to a wave at a boundary between two materials?

  • Reflected
  • Absorbed
  • Transmitted
• What is the law of reflection?

  The angle of incidence equals the angle of reflection
• What factors affect the strength of a reflected wave?

  Smoother surfaces produce stronger reflections
• What occurs during transmission of a wave?

  The wave passes through a substance and emerges
• What happens to a wave's amplitude during transmission?

  It may decrease due to absorption
• What occurs during absorption of a wave?

  Energy is transferred to the particles of a substance
• How does light absorption relate to color perception?

  Only reflected light determines color appearance
• What does it mean if an object appears red?

  Only red light has been reflected
• experiment: speed of sound


  1. set up an oscilloscope so the detected waves at each microphone are shown as separate waves.
  2. start with both microphones next to the speaker, then slowly move one away until the two waves are aligned on the display, but have moved exactly one wavelength apart.
  3. measure the distance between the microphones to find one wavelength
  4. use the formula: wave speed = frequency x wavelength to find the speed of the sound waves.
  5. the frequency is what you set on the signal generator in the first place.
• experiment: frequency [ripple tank]

  1. float the cork in the ripple tank. it should bob up and down as the waves pass it.
  2. when the cork is at the top of a 'bob', start the stopwatch.
  3. count how many times the cork bobs in a fixed period of time e.g. 20 seconds.
  4. divide this number by your time interval (how long you counted for) to get the number of 'bobs' per second - the frequency
• experiment: wavelength


  1. place a card covered centimetre-squared paper behind the ripple tank.
  2. turn on the strobe light and adjust its frequency until the waves appear to 'freeze'
  3. using the squared paper, measure the distance that e.g. 5 waves covers.
  4. divide this distance by the number of waves to get an average wavelength.
• experiment: wave speed


  1. place a large piece of paper next to the tank
  2. as the waves move across the tank, on of you should track the path of one of the crests on the paper, using a pencil.
  3. make sure the lines is straight and parallel to the direction the wave travels.
  4. the other person should time how long the first has been drawing for. pick a duration e.g. 10 seconds, and stop drawing when the time has passed.
  5. calculate the speed by measuring the length of the lines. use the formula: distance travelled = speed x time.