This topic covers what waves are, how to describe them with wavelength, frequency, amplitude and speed, and what happens when a wave meets a boundary. It also asks you to tell transverse from longitudinal waves and to read wave diagrams carefully.
The exact content and depth depend on your syllabus year. Check the current Cambridge IGCSE Physics 0625 page for your exam year. The Physics learning guide shows where this module sits in the whole subject.
What do I need to know first?
You need comfortable unit handling from measurement and quantities: converting cm to m, kHz to Hz and minutes to seconds. You also need the idea of speed and how to rearrange a three-quantity equation, which you met in motion and graphs.
Energy transfer from work, energy and efficiency helps too, because waves carry energy from place to place without moving material along.
One orienting worked example
A ripple tank produces 10 waves in 2.5 s. The distance across 4 complete waves is 0.20 m. (Invented example data.) Find the wave speed.
Step 1, frequency: f = 10 ÷ 2.5 = 4.0 Hz.
Step 2, wavelength: λ = 0.20 ÷ 4 = 0.050 m.
Step 3, equation: v = f × λ = 4.0 × 0.050 = 0.20 m/s.
Step 4, check: 0.20 ÷ 4.0 = 0.050 m, which matches the wavelength. The answer is 0.20 m/s.
Every lesson in this module adds one careful habit to those four moves: convert units, count gaps, read from the rest position and explain what stays the same.
In what order should I study the lessons?
- Connect wavelength, frequency and speed: the core equation and the unit habits everything else uses.
- Read amplitude without doubling it: what the height of a wave means and what it does not change.
- Explain reflection and refraction using wavefronts: which quantities change at a boundary and which stay fixed.
- Distinguish transverse and longitudinal motion: the vibration direction test and how to measure wavelength in each.
- Interpret a ripple-style diagram without assuming scale: counting gaps and trusting only the stated numbers.
Then test yourself with the wave behaviour practice set. The module after this one is light and imaging, which uses reflection and refraction directly.
Which traps catch most students?
- Using the length of several waves as one wavelength.
- Leaving wavelength in centimetres or frequency in kilohertz inside v = f × λ.
- Reading amplitude from crest to trough instead of from the rest position.
- Saying the frequency changes when a wave is refracted.
- Measuring angles from the surface instead of from the normal.
- Saying that particles in a sound wave travel from the source to the listener.
How should I use the practice set?
Write the equation, the converted units and the answer with its unit before opening each worked answer. Use the error-routing section at the end to return to the right lesson. Afterwards, log any repeated slip in the mistake log and retest queue so it comes back later as a fresh question.
Students who know the equation yet still lose marks on diagrams or explanations can gain from a teacher reading their working as it is written. That is what our online one-to-one Physics tuition is designed to offer.