Frequency of a matter wave is equal to

By de-Broglie equation

$\mathrm{\lambda }=\frac{\mathrm{h}}{\mathrm{mv}}$

For a matter wave

$\begin{array}{l}\text{ Frequency, }\mathrm{v}=\frac{\text{ velocity }\left(\mathrm{v}\right)}{\mathrm{\lambda }}=\frac{\mathrm{v}}{\mathrm{h}/\mathrm{mv}}\\ \mathrm{v}=\frac{{\mathrm{mv}}^2}{\mathrm{h}}\\ \text{ Since, }\mathrm{KE}=\frac{1}{2}{\mathrm{mv}}^2\\ \therefore {\mathrm{mv}}^2=\frac{2\mathrm{KE}}{\mathrm{h}}\\ \text{ Frequency, }\mathrm{v}=\left(\frac{2\mathrm{KE}}{\mathrm{h}}\right)\end{array}$