ANSWER:
1.757 mm
STEP-BY-STEP EXPLANATION:
The coefficient of linear expansion is given by the following formula:
[tex]\alpha=\frac{\Delta L}{L\Delta T}[/tex]Where α = coefficiente of linear expasion, ΔL = change in lenght, ΔT = change in tempetature
Solving for ΔL:
[tex]\Delta L=\alpha\cdot L\cdot\Delta T[/tex]Replacing and we calculate the change in lenght:
[tex]\begin{gathered} \Delta L=12\cdot10^{-6}\cdot12.62\cdot(30.6-19) \\ \Delta L=0.001757\text{ m}\cdot\frac{1000\text{ mm}}{1\text{ m}}=1.757\text{ mm} \end{gathered}[/tex]The change in length is 1.757 mm