De broglie wavelength of fast moving particle--help please! 1. The problem statement, all variables and given/known data A particle moving with kinetic energy equal to its rest energy has a de Broglie wavelength of 1.7898 *10^-16 m. If the kinetic energy doubles, what is the new de Broglie wavelength? 2. Relevant equations λ=h/√(2mK) m=m0γ K=Et-E0 3. The attempt at a solution Initially: K=m0c2=ET-m0c2 But ET=m0c2γ thus: 2=γ, which implies v=1/2(√3) λ=h/√(2mK)=h/√2m0γ*m0c2= h/(2m0c) Then when the K becomes twice the rest mass: K=Et-E0 3m0c2=m0c2γ, which implies γ=3 so λ=h/√(2m0γK)=h/√2m0*3*(2m0c2 =h/(2m0c*√3), which is just the original λ divided by the root of 3. 1.7898/√3= 1.03, so λ=1.033*10^-16, but the answer is λ=1.096*10^-16 Please help-- I have been wracking my brains about this for two days!