p⃗ = mv⃗

p⃗ = γmv⃗

p = γmv

\frac{p}{m} = γv

Q ≡ \frac{p}{m}

γv = Q

γ^{2}v^{2} = Q^{2}

(\frac{1}{1 − v^{2}/c^{2}} )v^{2} = Q^{2}

v^{2} = (1 − v^{2}/c^{2})Q^{2}

v^{2} = Q^{2} − v^{2} (\frac{Q^{2}}{c^{2}} )

v^{2} + v^{2} (\frac{Q^{2}}{c^{2}} ) = Q^{2}

v^{2}(1 + \frac{Q^{2}}{c^{2}} ) = Q^{2}

v^{2} = \frac{Q^{2}}{1 + \frac{Q^{2}}{c^{2}}}

v = \sqrt{\begin{matrix}(p/m) & 2 \\ ( & 1 + \frac{(p/m)^{2}}{c^{2}} & ) \end{matrix}}

p ≃ γmc

\begin{aligned}p & ≃ γmc \\ E & = γmc^{2} \end{aligned}

\begin{aligned}pc & ≃ γmc^{2} = E \\ p & ≃ \frac{E}{c} \end{aligned}

E = (rest energy) + (kinetic energy)
=  (1)mc^{2}  + (γ − 1)mc^{2}

p = \frac{E}{c}

E = hν = h\frac{c}{λ}