Question

A rod of mass $m$ and length $l$ is acted upon by two forces each of magnitude $F$ as shown in the figure. The length of the rod is $l$, area of cross section is $A$, the youngs moduls of the material is $y$. select correct alternative

• A. The stress in rod at a distance $\frac{l}{4}$ from one end is $\frac{F}{2A}$
• B. Net change in length of the rod is $\frac{Fl}{AY}$
• C. The stress in rod at mid point of the rod is $\frac{F}{A}$
• D. Total elastic potential energy stored in the rod is zero.

Answer 1

The correct option is C The stress in rod at mid point of the rod is $\frac{F}{A}$

$\begin{array}{c}\text{Mass of rod}=m\\ \text{length}=L\\ \text{Force}=F\\ \text{Area of crossection =}A\\ \text{Young's mudulus =}y\end{array}$

$\begin{array}{cc}\text{Stress}& =\frac{\text{Force}}{\text{Area}}\\ & =\frac{F}{A}\end{array}$