$A$ heavy nucleus at rest breaks into two fragments which fly off with velocities in the ratio $8 : 1$. The ratio of radii of the fragments is

How many times is the density of the nucleus more than the density of water?

Calculate the height of the potential barrier for a head-on collision of two deuterons. (Radius of deuteron is $2$ fm).

Assume that protons and neutrons have equal masses. The mass of a nucleon is $1.6 \times 10^{-27} \ kg$ and the radius of a nucleus is $R = 1.5 \times 10^{-15} A^{1/3} \ m$. The approximate ratio of the nuclear density to the water density is $n \times 10^{13}$. The value of $n$ is $.................$

The radius of germanium $(Ge)$ nuclide is measured to be twice the radius of ${ }_4^9 Be$. The number of nucleons in $Ge$ will be