c
\({E_{ex2}}\, = \,\,\,108.8\,V\)

\(\because\) \(p\,\, = \,\,\frac{E}{c}\,\, = \,\,\frac{{108.8\,\, \times \,\,1.6\,\, \times \,\,{{10}^{ - 19}}}}{{3\,\, \times \,\,{{10}^8}}}\)

\( = \,\,5.8\,\, \times \,\,{10^{ - 26}}\,\,kg - m/s\)

\(\because\) \(\,\,E\,\, = \,\,\frac{{{p^2}}}{{2M}}\,\)

\(\,\, = \,\,\frac{{{{5.8}^2} \times \,\,{{10}^{ - 52}}}}{{2\,\, \times \,\,7\,\, \times \,\,1.67\,\, \times \,\,{{10}^{ - 27}}}}\,\,\)

\( = \,\,1.44\,\, \times \,\,{10^{ - 25}}\,\,J\)