For example, in the fission process:
$${}^{235}\mathrm{U} + n \rightarrow {}^{140}\mathrm{Xe} + {}^{94}\mathrm{Sr} + 2n$$
the masses in atomic mass units are:
\begin{align} M\left({}^{235}\mathrm{U}\right) &= 235.04393 \\ M(n) &= 1.008665 \\ M\left({}^{94}\mathrm{Sr}\right) &= 93.915361 \\ M\left({}^{140}\mathrm{Xe}\right) &= 139.92164 \end{align}
Therefore, the energy released is:
\begin{align} &\left[M\left({}^{235}\mathrm{U}\right) + M(n) - M\left({}^{94}\mathrm{Sr}\right) - M\left({}^{140}\mathrm{Xe}\right) - M(2n)\right] \times 931.5 \,\mathrm{MeV} \\ &= 0.22251 \times 931.5 \,\mathrm{MeV} \\ &= 208.2 \,\mathrm{MeV} \\ \end{align}
How do I change 208.2 MeV to velocity (m/s)?