A rod of radius 2mm,length 80cm density $5KKg/m^3$ and made up of material of $Y=1\times 10^{10}N/m^2$.Find the elongation due to its own weight.

Question

$\begin{array}{1 1}(A)\;1.6\times 10^{-6}m\\(B)\;3.2\times 10^{-6}m\\(C)\;2.4\times 10^{-6}m\\(D)\;\text{Zero}\end{array}$