KE = \frac{1}{2}mv^{2}

KE = (γ − 1) mc^{2}

γ = \frac{1}{\sqrt{1 − \frac{v^{2}}{c^{2}}}}

\frac{v}{c} = β = \sqrt{1 − \frac{1}{γ^{2}}}

rest energy = mc^{2}

total energy E = rest energy + KE

= (mc^{2}) + (γ − 1) mc^{2}

= γmc^{2}

Po^{210} → Pb^{206} + He^{4}