A student sends a wave along a rope by moving one end up and down repeatedly. Describe the key properties of this wave, including what is meant by amplitude, frequency and wavelength.

WJEC A-Level Physics (Wales) — 3.1 Wave properties · Describe · 5 marks · View as Markdown

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

Model answer (5 marks)

Amplitude is the maximum displacement of a point on the rope from its rest position.
Frequency is the number of complete waves (cycles) produced per second.
Wavelength is the distance between two successive points that are in phase, such as crest to crest or trough to trough.
The wave is transverse: the rope particles oscillate perpendicular to the direction of energy transfer, so the rope itself does not move along the rope.
The wave speed is related to frequency and wavelength: v = f × λ, so a higher frequency or a longer wavelength gives a faster wave.

Examiner tips

  • Use the exact definitions of amplitude, frequency and wavelength. Mention that the wave is transverse and that energy is transferred without the rope moving. Include the relationship v = f × λ to show understanding of wave speed.
  • common_mistakes
  • :
  • Confusing amplitude with wavelength or frequency. Forgetting that the rope does not move along the rope. Omitting the wave speed formula or mis‑stating it.

Mark scheme (5 marks)

  1. Amplitude is the maximum displacement of a point on the wave from its rest (equilibrium) position
  2. Frequency is the number of complete waves (cycles) produced per second
  3. Wavelength is the distance between two successive points that are in phase (e.g. crest to crest or trough to trough)
  4. The wave transfers energy along the rope without the rope itself moving along (particles oscillate perpendicular to the direction of energy transfer, making it a transverse wave)
  5. The wave speed is related to frequency and wavelength: a higher frequency or longer wavelength produces a faster wave (wave speed = frequency × wavelength)

Key terms in this question

amplitude · frequency · wavelength

Related

More Wave properties questions

▶ Try answering this question with AI marking (free) →