Find the matter wavelength λ = h / (m v) of a particle treated as a wave.
| λ (m) | – |
| λ (nm) | – |
Use this calculator for the non-relativistic de Broglie relation: wavelength is Planck’s constant divided by momentum p = m v. An electron of mass 9.109×10⁻³¹ kg at 10⁶ m/s has λ around 0.73 nm, atomic size. A baseball’s wavelength is absurdly small.
This is not relativistic: if speed is a large fraction of c, momentum is γ m v, not m v. Mass and speed must be greater than zero. The nanometre output is λ × 10⁹.
Mass (kg): Particle mass in kilograms. Electron ≈ 9.109e-31 kg.
Speed (m/s): Speed well below c for this formula, in metres per second.
λ (m): de Broglie wavelength in metres.
λ (nm): The same wavelength in nanometres.
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