Answer:
100.11 m
Explanation:
Given:
Coefficient of volume expansion, [tex]\alpha_{v}=33\times10^{-6}[/tex] /°C.
Initial length of rod, [tex]l=100 m[/tex]
Change in temperature, ΔT=[tex](90-(-10))=100[/tex] °C
We know that,
[tex]\alpha_{v}=3\alpha_{L}\\\alpha_{L}=\frac{\alpha_{v}}{3}\\\alpha_{L}=\frac{33\times10^{-6}}{3}=11\times10^{-6}[/tex] /°C
Here, [tex]\alpha_{L}[/tex] is the coefficient of linear expansion.
Now, we know that,
Change in length (Δl) is given as,
[tex]\Delta l=\alpha_L\times L\times\Delta T[/tex]
Plug in all the values and solve for [tex]l[/tex].
This gives,
[tex]\Delta l=11\times10^{-6}\times 100\times100\\\Delta l=0.11 \textrm{ m}[/tex]
Therefore, the length of rod after expansion is [tex]L+\Delta l=100+0.11=100.11[/tex] m.