A uniform steel rod of mass 1.8 kg and length 0.8 m is hung from a nail with the help of a steel wire of area of cross-section 0.01 `mm^(2)` and unstretched length of 1m as shown in the figure. the centre of mass of the rod lies vertically below the nail. The increase in the distance between the centre of mass of the rod and the nail due to stretcheing of the wire as the rod huns is____mm. (young.s modulus of steel `=2xx1011Nm^(-2)` and acceleration due ot gravity `=10ms^(-2)`

Options

A. 50
B. 25
C. 12.5
D. 6.25

Answer

4