Part 1: Observing water waves in a ripple tank

• What is a ripple tank?

  A shallow glass tank for creating waves
• How are waves created in a ripple tank?

  By an oscillating paddle or needle
• Why is the ripple tank illuminated from above?

  To see the waves on the surface below
• What are the basic steps of the ripple tank practical?

  1. Set up the ripple tank with a lamp and card
  2. Switch on the motor attached to the rod
  3. Measure the wavelength of the waves
  4. Count waves passing a point in 10 seconds
  5. Calculate the frequency and wave speed
• How deep should the water be in the ripple tank?

  Around 5 mm
• What happens if there is too much water in the ripple tank?

  Clear waves won't be produced
• How should the wooden rod be positioned in the ripple tank?

  It should just touch the water's surface
• How do you measure the wavelengths of the waves on the card?

  1. Adjust the lamp for clear projection
  2. Measure across as many waves as possible
  3. Divide the distance by the number of waves
• In what units should wavelength be measured?

  Metres, m
• Why is it better to measure across more than one wave?

  To reduce uncertainty and improve accuracy
• How do you measure the frequency of the waves on the card?

  1. Count waves passing a point in 10 seconds
  2. Divide the number by 10 for frequency in Hz
• What is the equation for calculating wave speed?

  Wave Speed = Frequency x Wavelength
• What is the unit for wave speed when frequency is in Hertz and wavelength in metres?

  Metres per second, m/s
• What is the alternative unit for measuring wavelength?

  Centimetres, cm