JEE Main202131 Aug 2021Morning ShiftPhysicsMechanical Properties of SolidsActual
A uniform heavy rod of weight 10 kg m s - 2 , cross-sectional area 100 cm 2 and length 20 cm is hanging from a fixed support. Young modulus of the material of the rod is 2 × 10 11 N m - 2 . Neglecting the lateral contraction, find the elongation of rod due to its own weight:
Options
- A5 × 10 - 10   m
- B4 × 10 - 8   m
- C5 × 10 - 8   m
- D2 × 10 - 9   m
Correct answer
A. 5 × 10 - 10   m
Step-by-step solution
Elongation due to self weight, W l 2 A Y = 10 × 0 . 2 2 × 2 × 10 11 × 100 × 10 - 4 = 5 × 10 - 10   m