Waves (O-Levels)

What these notes cover

These notes introduce the general properties of waves for Cambridge O Level Physics (5054) and Cambridge IGCSE Physics (0625): how waves transfer energy without transferring matter, the difference between transverse and longitudinal waves, and the key terms amplitude, wavelength, frequency and wavefront. They also cover reflection, refraction and diffraction, as seen in a ripple tank.

Key formulas and definitions

• Wave speed: v = fλ
• Frequency is the number of complete waves passing a point per second (Hz): f = 1/T
• Transverse wave: vibrations are perpendicular to the direction of energy transfer (e.g. light, water waves).
• Longitudinal wave: vibrations are parallel to the direction of energy transfer (e.g. sound).
• Amplitude: the maximum displacement of a point from its rest position.
• Wavelength (λ): the distance between two neighbouring crests (or compressions).
• Refraction is a change in direction caused by a change in wave speed, e.g. water waves moving from deep to shallow water.
• Diffraction is greatest when the gap width is similar to the wavelength.