Work out de broglie wavelength instantly with clear inputs, formula shown and shareable results.
Every particle has a wavelength lambda = h/p. An electron at 1e6 m/s has a momentum of 9.11e-25 kg m/s and a wavelength of 7.27e-10 m - about the size of an atom, which is exactly why electron diffraction reveals crystal structure. A tennis ball's wavelength is around 1e-34 m, far too small to observe.
de Broglie relation
lambda = h / p = h / (m v)
Momentum
p = m v (non-relativistic)
Because h is tiny. A 60 g ball at 20 m/s has a wavelength of about 5.5e-34 m, twenty orders of magnitude below anything measurable.
Because a 100 keV electron has a wavelength near 4 pm, thousands of times shorter than visible light, so the diffraction limit is far finer.