Ripple Tank
Frequency, Velocity, and Wavelength
There is a distinct relationship between frequency, wave velocity, and wavelength. If you know any two, you can determine the third simply by using the formula v = fλ
Purpose: To study the relationship between velocity, wavelength, and frequency.
Procedure to set up the ripple tank
  1. Level the tank by screwing the feet in or out, using the level provided.
  2. Fill the tank to a depth of about 0.5 cm.
  3. Attach the plane wave actuator bar to the ripple generator.
  4. Do not touch the phase control! You don’t need to adjust it!
  5. Position the wave generator so that the actuator bar is just touching the surface of the water. Connect the wave generator to the power supply.
  6. Turn the power supply on and adjust the current to get the slowest moving waves you can without turning the actuator bar off.
  7. Turn on the light and use it to project the image of the waves.Place a ruler and a running stopwatch under the wave tank.
  8. Record the wage images moving under the tank (in slow motion is possible).
  9. Count the number of waves to pass a point on the table in 10 seconds. Record the frequency of the waves in the table below.
  10. Measure and record the wavelength of the water waves on the table below.
  11. Turn off the power supply but do not adjust any of the knobs.
  12. Add water to the tank until the depth is about 1.5 cm and repeat steps 5-11.
  13. Add water to the tank to a depth of about 3 cm and repeat steps 5-11.
  14. Repeat steps 2-13with the actuator bar turned on higher.
Water Depth / frequency (Hz) / wavelength (m)
Questions:
  • What do you notice about the relationship between the frequency and the wavelength?
  • Calculate the velocity of the waves using the data in the table.
  • What do you notice about the velocity of the wave as the frequency changes?
  • How does the depth of the water affect frequency, wavelength, and wave velocity?
  • How does energy put into the waves affect frequency, wavelength, and wave velocity?
  • The velocity should have been the same for all frequencies. Was it? If not, what are some sources of error that could have affected the results?