Question

A uniform slender rod of length $L$, cross-sectional area $A$ and Young's modulus $Y$ is acted upon by the forces shown in the figure. The elongation of the rod is

• A. $\frac{3 F L}{5 A Y}$
• B. $\frac{2 F L}{5 F Y}$
• C. $\frac{3 F L}{8 A Y}$
• D. $\frac{8 F L}{3 A Y}$

Answer 1

Answer: (D)

Net elongation of the rod is
$l=\frac{3 F\left(\frac{2 L}{3}\right)}{A Y}+\frac{2 F\left(\frac{L}{3}\right)}{A Y}$
$l=\frac{8 F L}{3 A Y}$