Required Practical 20: Waves

About this practical...

Waves is a subject that is helped massively if you can visualise what is happening. By using a ripple tank, you can see the waves, measure wavelength, wave speed and frequency and even visualise red-shift. By showing a stationary wave on a stretched wire, you can see the wave forms which will help to explain resonance.


For this required practical, you need to use a ripple tank or see one working. They are not the easiest pieces of apparatus and I am not a huge fan of them. As well as seeing the ripple tank in class, please experiment with a ripple tank simulator.

1. The ripple tank is set up on an overhead projector. Turn on the light and ensure that it is in focus on the white board. Students will not be allowed to add/drain water due to its proximity to the lights.

2. On the whiteboard, mark out the dimensions of the projected tank and create a scaled rule

3. Turn on the wave generator and record the settings.

4. Use the scale on the board to measure the wavelength

5. Using a stop clock, measure the frequency

6. Using the stop clock, measure the wave speed

7. Assess the accuracy of your measurements by seeing if they fit into the equation - Frequency = Wave Speed x Wavelength

8. Repeat for other settings/frequencies

For the second part of this, you will be investigating a stationary wave. The equipment will be setup for you to use.

1. Turn on the generator and adjust the frequency until you have a half wavelength stationary wave. Record this frequency and measure/record the length of the stationary wave (this will be half of the wavelength)

2. Adjust until you find (and record) a full wavelength and any others that you can achieve.

Safety & Managing Risks

Usual lab rules must be followed: Bags and stools tucked away and notify the teacher of any spills or breakages immediately. Take care of the proximity of water to the sources of electricity. For more detailed information, please consult CLEAPSS.

Technician notes:

Ripple tank mounted on OHP

Power supply

Boundary blocks/curved edges

This page was updated on: 8th January 2022