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In a transverse wave, how do the particles move?
Waves is a core part of IB Physics. Revise the key concepts and common mistakes below, then lock them in with the free games.
Key concepts
Transverse & longitudinal wavesVibrations perpendicular (light) or parallel (sound) to travel.
Frequency & wavelengthNumber of waves per second and the length of one wave.
Wave speedv = f × λ, the speed a wave travels.
AmplitudeMaximum displacement from the rest position; relates to energy.
Electromagnetic spectrumRadio to gamma; all travel at the speed of light in a vacuum.
Reflection & refractionWaves bounce off surfaces or change direction when changing medium.
Simple harmonic motiona = -omega^2 x; sinusoidal in time; T = 2 pi / omega; pendulum and mass-spring examples.
Single slit diffractionCentral maximum width 2 lambda L / b; minima at sin theta = n lambda / b.
Double slit interferenceFringe spacing s = lambda L / d (Young 1801); evidence for wave nature of light.
Diffraction gratingd sin theta = n lambda; sharp principal maxima used in spectroscopy.
Resolution (Rayleigh)Two sources just resolved when central max of one coincides with first min of other; theta = 1.22 lambda / D.
PolarisationRestriction of transverse oscillations to one plane; Malus' law I = I0 cos^2 theta (Malus 1809).
LLearn Waves step by step
Free interactive mini-lessons: short screens, worked examples and quick checks. Pick your exam board:
Common mistakes to avoid
Questions where students often pick the tempting wrong answer — make sure you know the right one:
In a transverse wave, how do the particles move?✗ In the same direction the wave travels. ✓ At right angles to the direction the wave travels.
Can sound travel through a vacuum?✗ Yes, sound travels through empty space. ✓ No — sound needs particles (a medium) to travel.
Practise Waves — free games
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