Question

A copper road whose length at 70°c is 4.0m is heated to 10°c find it

Answer 1

Given:

$l_0=4.0\;\rm m$

$\Delta T=30\:\rm K$

$\alpha=17*10^{-6}\:\rm K^{-1}$

The thermal linear expansion is described by an equation

$$\Delta l=l_0\alpha\Delta T\\ =\rm4.0\: m*17*10^{-6}\:\rm K^{-1}*30\: K=0.002\: m=2\: mm$$