Recall that waves transfer energy and information without transferring matter

Describe evidence that with water and sound waves it is the wave and not the water or air itself that travels

Define and use the terms frequency and wavelength as applied to waves

Use the terms amplitude, period, wave velocity and wavefront as applied to waves

Describe the difference between longitudinal and transverse waves by referring to sound, electromagnetic, seismic and water waves

Recall and use both the equations below for all waves:

wave speed (metre/second, m/s) = frequency (hertz, Hz) × wavelength (metre, m)

\(v = f × \lambda\)

wave speed (metre/second, m/s) = distance (metre, m) ÷ time (second, s)

\(v = \dfrac{x}{t}\)

Describe how to measure the velocity of sound in air and ripples on water surfaces

Calculate depth or distance from time and wave velocity

Describe the effects of:

a) reflection
b) refraction
c) transmission
d) absorption

of waves at material interfaces

Explain how waves will be refracted at a boundary in terms of the change of direction and speed

Recall that different substances may absorb, transmit, refract or reflect waves in ways that vary with wavelength

Describe the processes which convert wave disturbances between sound waves and vibrations in solids, and

a) explain why such processes only work over a limited frequency range
b) use this to explain the way the human ear works

Recall that sound with frequencies greater than 20,000 hertz, Hz, is known as ultrasound

Recall that sound with frequencies less than 20 hertz, Hz, is known as infrasound

Explain uses of ultrasound and infrasound, including

a) sonar
b) foetal scanning
c) exploration of the Earth’s core

Describe how changes, if any, in velocity, frequency and wavelength, in the transmission of sound waves from one medium to another are inter-related

Core Practical: Investigate the suitability of equipment to measure the speed, frequency and wavelength of a wave in a solid and a fluid