A uniform heavy rod of weight 10 kg ms–2, cross-sectional area 100 cm2 and length 20 cm is hanging from a fixed support. Young modulus of the material of the rod is 2 × 1011 Nm–2. Neglecting the lateral contraction, find the elongation of rod due to its own weight.
(1) 2 × 10–9 m
(2) 5 × 10–8 m
(3) 4 × 10–8 m
(4) 5 × 10–10 m