A nuclear physicist performed an experiment on the scattering of alpha particles by thin metal foil of gold. The alpha particles were accelerated up…

A nuclear physicist performed an experiment on the scattering of alpha particles by thin metal foil of gold. The alpha particles were accelerated up to kinetic energy $\displaystyle 3.2$ Mev . The estimation of the radius of the nucleus of gold element $\displaystyle (\mathrm{Z}=79)$ by him is \_\_\_\_ $\displaystyle \times 10^{-16} \mathrm{~m}$ $\displaystyle \left(\right.$ Take $\displaystyle \left.\frac{1}{4 \pi \epsilon_o}=9 \times 10^9 \frac{\mathrm{Nm}^2}{\mathrm{C}^2}\right)$