Question

The coefficient of linear expansion of steel is 12 × 10-6 K-1. What is the change in length of a 25-m steel bridge span when it undergoes a temperature change of 40 K?

Answer 1

In order to calculate the change in length, we can use the following formula:

$\delta L=L_0\cdot\alpha\cdot\Delta T$

Where deltaL is the change in length, L0 is the initial length, alpha is the coefficient of linear expansion and DeltaT is the change in temperature.

So we have:

$\begin{gathered} \delta L=25\cdot12\cdot10^{-6}\cdot40 \\ \delta L=120000\cdot10^{-6} \\ \delta L=12\cdot10^{-2}=0.12 \end{gathered}$

So the change in length is 0.12 meters or 12 centimeters.