P6: waves

• Describe waves as either transverse or longitudinal, defining these waves in terms of the direction of their oscillation and energy transfer and giving examples of each

  | transverse waves

  • perpendicular (90°) vibrations to direction of energy transfer
  • eg: all EM waves, light, ripples & waves

  | longitudinal waves

  • parallel vibrations
  • eg: sound waves in air
• wave speed= frequency x wavelength

  wave speed= m/s

  frequency= Hz

  wavelength= m
• T=1/f

  T= period (s)

  f= frequency (Hz)
• Describe waves as transfers of energy from one place to another, carrying information
• Define amplitude, wavelength, frequency, period and wave speed & Identify them on diagrams

  • amplitude: max displacement from it's resting point
  • wavelength: distance between same points of 2 adjacent waves
  • frequency: number of complete waves per second
  • period: time taken for 1 full wave cycle
  • wave speed: speed at which energy is being transferred/ speed wave is moving at
• define amplitude, wavelength, frequency, period and wave speed & identify them on diagrams


  • amplitude: max displacement from it's resting point
  • wavelength: distance between same points of 2 adjacent waves
  • frequency: number of complete waves per second
  • period: time taken for 1 full wave cycle
  • wave speed: speed at which energy is being transferred/ speed wave is moving at

  
• examples of methods of msring wave speeds in different media & suitability of apparatus of msring frequency and wavelength

  ⊹ 𝓸scilloscope

  1. set up oscilloscope so detected waves @ each mic shown as sepr8 waves
  2. start w/ mics next to spkr then slowly move 1 away until 2 waves align & moved exactly a wavelength apart
  3. msr dist betw mics= wavelength (λ)
  4. use v=fλ to find spd (v)_ freq= wtv u set signal gen to (1KHz is good)
  5. spd of sound in air $\approx$330m/s so results shld roughly agree w/ that

  
• examples of methods of msring wave speeds in different media & suitability of apparatus of msring frequency and wavelength

  ⊹ 𝓻ipple 𝓽ank

  1. w/ signal gen attached to dipper, u can cr8 waves waves @ set freq
  2. dim the lights, turn on lamp_ should see wave crests as shadows on screen
  3. msr dist betw 10 wavelengths, ÷ by 10= avg wavelength
  4. use v=fλ to calc spd

  • SUITABLE for msring wavelengths of moving waves or small wavelengths
  • set up is SUITABLE bc you can msr wavelength without disturbing waves
• examples of methods of msring wave speeds in different media & suitability of apparatus of msring frequency and wavelength

  ⊹ 𝔀aves 𝓸n 𝓼trings

  1. adjust frequency of signal genr8r until there's a clear wave on the string.

  ﹥freq depends on length of string betw pulley & transducer and masses used

  2. msr wavelength

  ﹥msr 4/5 half wavelengths and ÷ to get mean half. 2x mean= avg full wavelength

  3. v=fy to calc spd, freq= wtv signal gen is set to