Waves
Wave Number
Spatial frequency of wave.
Variables
krad/m
Wave number
Radians per meter
Allowed values: greater than 0
λm
Wavelength
Distance between crests
Allowed values: greater than 0
Derivation
k = 2π/λ, analogous to ω = 2π/T.
Your notes
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Check value
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- λ = 2 m (Wavelength)
Result: k = 3.1415927 rad/m
Other waves formulas with the same quantities
- Group Velocity (Wave Properties) shares Wave number
- Phase Velocity (Wave Properties) shares Wave number
Where this formula is listed
- Waves formulas, under Wave Properties, alongside Period and Frequency, Wave Intensity, Intensity-Amplitude Relation, Inverse Square Law (Intensity) and Wave Speed on String.
- In the waves list it comes after Angular Frequency and before Wave Intensity.
- Waves formula sheet, one of 37 formulas printed with symbol keys and SI units.
- The full formula index, grouped by category and topic.
Common questions
What is the Wave Number formula?
Wave Number is written k = 2π/λ. Spatial frequency of wave. It belongs to Waves, under Wave Properties.
What are the units in k = 2π/λ?
In SI units, k is wave number, measured in rad/m; λ is wavelength, measured in m.
How is the Wave Number formula derived?
k = 2π/λ, analogous to ω = 2π/T. The result is k = 2π/λ.