
Brandon B. answered 03/03/21
Physics PhD. 10+ years teaching calculus based physics.
The de Broglie wavelength of a particle of mass m is given by λ = h/(mv), where h is Planck's constant. Kinetic energy is Ek = mv2/2 ⇒ 2mEk = (mv)2 ⇒ mv = (2mEk)1/2 ⇒ λ = h/(2mEk)1/2 ⇒ Ek = h2/(2mλ2).