The Young's modulus of a steel wire of length 6 m and cross-sectional area 3 mm^2, is 2 × 10^11 N / m^2. The wire is suspended from its support on a…

The Young's modulus of a steel wire of length $\displaystyle 6$ m and cross-sectional area $\displaystyle 3 \mathrm{~mm}^2$, is $\displaystyle 2 \times 10^{11}$ $\displaystyle \mathrm{N} / \mathrm{m}^2$. The wire is suspended from its support on a given planet. A block of mass $\displaystyle 4$ kg is attached to the free end of the wire. The acceleration due to gravity on the planet is $\displaystyle \frac{1}{4}$ of its value on the earth. The elongation of wire is (Take g on the earth $\displaystyle =10 \mathrm{~m} / \mathrm{s}^2$ ) :