Q. A rubber cord $10\ m$ long is suspended vertically. How much does it stretch under its own weight (Density of rubber is $1500\ kg/m^{3},Y = 5 \times 10^{8}N/m^{2},g = 10\ m/s^{2})$
A) $15 \times 10^{- 4}m$
B) $7.5 \times 10^{- 4}m$
C) $12 \times 10^{- 4}m$
D) $25 \times 10^{- 4}m$
Explanation
(a) $l = \frac{L^{2}dg}{2Y} = \frac{(10)^{2} \times 1500 \times 10}{2 \times 5 \times 10^{8}} = 15 \times 10^{- 4}m$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.