# Physics / Science GCSE: Measure the frequency, wavelength and speed of waves in a ripple tank

A demonstration of the key points of the required practical to measure the frequency, wavelength and speed of waves in a ripple tank for GCSE physics and combined science.

Students are unlikely to have come across a ripple tank before KS4 so this short film explores its key features and how they can be used to measure the characteristics of waves in water. It demonstrates how each of the factors can be measured and/or calculated.

The film also highlights the equation v=f λ which students need to make their calculations and will need be able to recall and apply.

### Teacher Notes

The practical allows development of Apparatus & Techniques Physics 4 (DfE GCSE subject content guidance, Appendix 4).

This short film can be used before or after introducing students to a ripple tank. It highlights the main features of a ripple tank and the information might have to be applied slightly differently depending on the ripple tank available in school.

The film demonstrates how to calculate frequency, wavelength and speed. Variations in how to make each measurement are highlighted, e.g. using the equation v=f λ rather than direct measurements to calculate wave speed.

Points for discussion:
Ripple tanks often vary in the way that they look, so this film highlights the key features common to all that are needed to measure frequency, wavelength and speed. This should help students to apply this knowledge to situations where the apparatus looks slightly different.

As this is often a demonstration rather than hands on practical activity in schools, students can find questions about the apparatus and suitability of the apparatus challenging.

Students must be able to recall and apply the equation v=f λ and the film provides opportunities to apply it using measurements taken from the ripple tank.

Suggested activities:
Using a slightly different set up of ripple tank will help students to apply the learning about common features and ways to measure variables to different situations.

Students should practise calculating frequency, wavelength and speed using different given measurements and by manipulating the equation where appropriate.

### Curriculum Notes

Suitable for teaching physics and combined science at Key Stage 4 and GCSE in England, Wales and Northern Ireland, and at National 4 and 5 in Scotland.