Question

A horizontal steel railroad track has a length of 100 m when the temperature is ${25}^{\circ }C$. The track is constrained from expanding or bending. The stress on the track on a hot summer day, when the temperature is ${40}^{\circ }C$, is (Note: The linear coefficient of thermal expansion for steel is $1.1\times {10}^{-5}{/}^{\circ }C$ and the Young’s modulus of steel is $2\times {10}^{11}Pa)$

• A.
• B.
• C.
• D.

Answer 1

The correct option is C

$\frac{F}{A}=Y\alpha \Delta T=2\times {10}^{11}\times 1.1\times {10}^{-5}\times 153.3\times {10}^{7}pa$