Measure wave speed
Measure frequency and wavelength using a ripple tank, string or sound setup, then calculate speed. Repeat measurements, use a clear scale and explain how reflections or parallax could affect the result.
GCSE Physics resources
AQA GCSE Waves
Waves Required Practical
Measure frequency and wavelength using a ripple tank, string or sound setup, then calculate speed. Repeat measurements, use a clear scale and explain how reflections or parallax could affect the result.
Start here
The quick revision snapshot
Measure frequency and wavelength using a ripple tank, string or sound setup, then calculate speed. Repeat measurements, use a clear scale and explain how reflections or parallax could affect the result.
By the end, you should be able to…
- Explain measure wave speed using precise physics language.
- Apply the relevant equations, diagrams or practical method to an exam-style situation.
- Use the mini quizzes and practice answers to identify and correct a misconception.
Core learning content
Learn the idea before you practise it
Start with this short teaching sequence for Waves Required Practical. Read the model, use the visual, then test your recall before moving into examples and exam practice.
Build the picture
Find wavelength by measuring several waves and dividing, rather than using one small gap. Measure frequency from the generator or a timed count, then calculate v = f lambda. Control tension or water depth where they could change wave speed and repeat measurements to reduce random variation.
Use the right relationship
Choose a relationship because of the physical change in the question, not because it is familiar. Wave speed: v = fλ (m/s, Hz, m). Period: T = 1 ÷ f (s, Hz). Magnification: magnification = image height ÷ object height (no unit). Keep the unit next to each value while you substitute.
What a strong answer does
State the apparatus, measurements, equation, control variables, repeats and one improvement linked to a named error. Before writing, underline the command word and identify the information that matters. Keep a calculation as equation, substitution and answer with unit; keep an explanation as a linked chain using because, so or therefore. Finish by checking that the final sentence answers the exact context in the question and that the number, direction or conclusion agrees with the evidence given.
Retrieval practice
Quick checks
Answer without looking back first. The feedback explains the model, so a wrong answer still helps you learn.
Mini quiz 1
Check the core idea
Mini quiz 2
Apply the model
Mini quiz 3
Use exam precision
Try it
Wave speed practical planner
Which measurements are needed to calculate wave speed?
What to notice: the readout and written explanation remain available if you do not use the controls.
Worked examples
See the method being built
Cover the answer, attempt the method and then compare your physics language as well as the number.
Example 1 · Several wavelengths
Five wavelengths on a string occupy 2.0 m. Find wavelength.
- Measure several cycles.
- Divide total length by 5.
- Give metres.
Show the answer
λ = 2.0 ÷ 5 = 0.40 m.
Example 2 · Calculate speed
Frequency is 8.0 Hz and wavelength 0.40 m. Find speed.
- Use v = fλ.
- 8.0 × 0.40.
- Give m/s.
Show the answer
v = 3.2 m/s.
Example 3 · Improve measurement
A student measures one crest gap with a ruler. Improve method.
- Identify small-distance uncertainty.
- Measure many waves.
- Divide by number.
Show the answer
Measure across several wavelengths and divide, reducing percentage uncertainty.
Misconception clinic
Common wrong turns
Each of these is tempting because it sounds almost right. Replace it with the precise physics before you meet it in a question.
- Measuring half a wavelength.
- Forgetting units in v = fλ.
- Changing water depth/tension during comparisons.
Independent practice
Exam-style questions
Use the working space first. Reveal the guidance only after you have committed to an answer, then improve the exact part that would gain the next mark.
1. State the equation used in the waves practical.
[1 mark]Show answer and marking guidance
v = fλ.
2. State one way to measure frequency.
[1 mark]Show answer and marking guidance
Use signal generator setting or count waves in a known time.
3. State one control variable for waves on a string.
[1 mark]Show answer and marking guidance
Tension in the string.
4. Why repeat wavelength measurements?
[2 marks]Show answer and marking guidance
To reduce random uncertainty and identify anomalies.
5. A wave has v = 12 m/s and f = 3.0 Hz. Find λ.
[2 marks]Show answer and marking guidance
λ = 12 ÷ 3.0 = 4.0 m.
6. Give one source of uncertainty and linked improvement.
[1 mark]Show answer and marking guidance
Parallax reading a ruler; view scale at right angles or use a fixed marker.
Questions pupils ask
GCSE Physics FAQs
What is the key idea in Waves Required Practical?
A wave transfers energy without transferring matter overall. Use diagrams to keep amplitude, wavelength, frequency, speed and direction distinct.
How should I practise Waves Required Practical?
Read the snapshot, attempt the worked examples without looking, complete the mini quizzes and then use the practice questions to check your wording and method.
Next step
Keep your revision moving
Physics sticks when you move between explanation, retrieval and application.