Explain the difference between transverse waves and longitudinal waves. In your answer, refer to the direction of oscillation and give one example of each type of wave.

AQA A-Level Physics (7408) — 3.3.1 Progressive and Stationary Waves · Explain · 5 marks · View as Markdown

Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).

Model answer (5 marks)

In a transverse wave the particles of the medium oscillate perpendicular to the direction of wave propagation.
In a longitudinal wave the particles oscillate parallel to the direction of propagation, producing alternating compressions and rarefactions.
A transverse example is a light wave.
A longitudinal example is a sound wave.

Examiner tips

Use the word "perpendicular" for transverse and "parallel" for longitudinal. Mention compressions/rarefactions for longitudinal. Give a clear example for each type. Keep the answer concise to fit the 5‑mark limit.

Common mistakes

Confusing the direction of oscillation with the direction of energy transfer. Using a non‑wave example such as a moving car. Omitting the compressions/rarefactions detail for longitudinal waves.

Mark scheme (5 marks)

In transverse waves, the oscillations/vibrations are perpendicular (at right angles) to the direction of travel/energy transfer.
In longitudinal waves, the oscillations/vibrations are parallel to (in the same direction as) the direction of travel/energy transfer.
Longitudinal waves have compressions and rarefactions (regions of high and low pressure).
A correct example of a transverse wave is given (e.g. any electromagnetic wave / light / water waves).
A correct example of a longitudinal wave is given (e.g. sound waves).

Key terms in this question

transverse waves · longitudinal waves