The Wave Equation

This lesson covers the wave equation — a key formula that links wave speed, frequency and wavelength. It is required by AQA GCSE Combined Science Trilogy (8464), Physics Paper 2, section 6.1. You must be able to recall this equation, rearrange it, and use it in calculations.

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The Wave Equation

$v = f \lambda$v=fλ

where:

• $v$v = wave speed in metres per second (m/s)
• $f$f = frequency in hertz (Hz)
• $\lambda$λ = wavelength in metres (m)

This equation tells us that the speed of a wave equals its frequency multiplied by its wavelength.

Exam Tip (AQA 8464): You must memorise this equation — it is not given on the AQA equation sheet. Write it at the top of your exam paper as soon as you open it.

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Rearranging the Equation

You need to be confident rearranging the wave equation to find any of the three quantities:

To find	Rearranged equation
Wave speed (v)	$v = f \lambda$v=fλ
Frequency (f)	$f = \dfrac{v}{\lambda}$f=λv​
Wavelength (λ)	$\lambda = \dfrac{v}{f}$λ=fv​