Answer:1.642 m
Step-by-step explanation:
Given
Initial Length of bridge [tex]L_0=3910 m[/tex]
temperature on cold day [tex]t_1=-5^{\circ}C[/tex]
temperature on hot day [tex]t_2=30^{\circ}C[/tex]
Change in temperature is [tex]\Delta T=30-(-5)=35^{\circ}C[/tex]
Coefficient of linear expansion of steel [tex]\alpha =12\times 10^{-6}/^{\circ}C[/tex]
and length after change in temperature is given by
[tex]L=L_0(1+\alpha \cdot \Delta T)[/tex]
[tex]\Delta =L_0\cdot \alpha \Delta T[/tex]
[tex]\Delta L=3910\cdot 12\times 10^{-6}\cdot 35[/tex]
[tex]\Delta L=1.642 m[/tex]