Question

A force of ${10}^{6}N/M^2$ is required for breaking a material. If density of the material is $3\times {10}^3$ $20kg/s^3$ .Then the length of wire made of material so that it breaks under its own weight is, $(g=10m/s^2)$

• A. $66.6m$
• B. $60.0m$
• C. $33.3m$
• D. $30.0m$

Answer 1

The correct option is C $33.3m$

$\text{Given, maximum stress wire can}$

$\begin{array}{c}\text{bear}={10}^{6}N/m^2\\ \text{Stress}=\frac{F}{A}\end{array}$

$\text{To break under its own weight,}F=mg$

$\begin{array}{cc}\frac{M\cdot g}{A}& =\frac{F}{A}={10}^6\\ \frac{dXV}{A}={10}^5& \Rightarrow d\times L={10}^5\\ L& =33.3m\end{array}$