Properties of waves

• Entry Level Certificate
• Learning objectives


  • Know what is meant by amplitude, wavelength, and frequency of a wave
  • Identify amplitude and wavelength on a diagram of a wave
  • Use the wave equation to calculate the speed of a wave
  • Understand how changes in frequency and amplitude affect a wave
  • Investigate how changing the frequency or amplitude of a wave changes the shape of a wave
  • Understand how frequency is related to the pitch of a sound wave
  • Understand how amplitude is related to the volume of a sound wave
• Amplitude


  The maximum displacement of a point on a wave away from its undisturbed position, measured in metres
• Wavelength


  The distance from a point on the wave to the same point on the next wave, measured in metres, centimetres, or millimetres
• Frequency


  The number of waves passing a point each second, measured in hertz or Hz
• The bigger the amplitude of a wave, the more energy it is transferring
• The speed of a wave is the distance travelled by each wave per second
• Calculate wave speed


  Wave speed (m/s) = frequency (Hz) x wavelength (m)
• Wave speed


  The distance travelled by each wave per second
• Frequency is measured in hertz or Hz
• Wavelength can be measured in metres, centimetres, or millimetres
• Amplitude is measured in metres
• The maximum displacement of a wave from its undisturbed position is called amplitude
• The distance between two peaks or two troughs is the wavelength
• The number of waves passing a point each second is called frequency
• The bigger the amplitude of a wave, the more energy the wave transfers
• Frequency is measured in hertz
• The speed of a wave can be calculated using the equation: wave speed = frequency x wavelength
• A speedboat on a lake sends waves travelling across the lake at a frequency of 2 Hz and a wavelength of 3.0 m
• Steps to calculate wave speed

  1. Step 1: Write down what you know

  2. Step 2: Write down the equation that links these values

  3. Step 3: Put the numbers in the equation and solve
• Figure 1 shows a diagram of a wave
• Figure 2 shows a ripple tank
• Figure 3 shows a wave travelling from left to right along a rope