Physics - Modern Physics Question with Solution | TestHub

The kinetic energy of the neutron beam$5\mathrm{eV}=\frac{1}{2}{\text{mv}}^2$

$\frac{1}{2}\left(1.67\times {10}^{-27}\right){\mathrm{v}}^2=5\times 1.6\times {10}^{-19}$

$\Rightarrow \mathrm{v}=31\mathrm{ }$$\mathrm{km} {\mathrm{s}}^{-1}$

distance travelled in one half-life$\mathrm{d}=\mathrm{vt}=31\times {10}^3\times 12.8\times 60 \mathrm{m}\simeq 24000\mathrm{ }\mathrm{km}\mathrm{ }$