How to Calculate Wavelength
What is Wavelength?
Wavelength is the distance between two consecutive peaks (or troughs) of a wave. Together with frequency and wave speed, it describes how waves travel through space. The formula λ = v/f relates all three.
Step-by-Step Guide
- 1λ = v / f (wavelength = wave speed / frequency)
- 2For electromagnetic waves: v = c = 3 × 10⁸ m/s
- 3Frequency f is in Hz (cycles/second)
- 4Wavelength λ is in metres
Worked Examples
Input
FM radio at 100 MHz
Result
λ = 3.0 m
3×10⁸ / 10⁸ = 3 m
Input
Red light at 700 nm
Result
f ≈ 4.3 × 10¹⁴ Hz
c / λ
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