Question

Calculate the change in length of a 100mm aluminium bar that has increased in temperature by 55⁰C.  

Take the coefficient of expansion to be 25 x 10^-6k^-1

Answer 1

Given:

$l_0=100\;\rm mm$

$\Delta T=55\:\rm K$

$\alpha=25*10^{-6}\:\rm K^{-1}$

The thermal linear expansion is described by an equation

$$\Delta l=l_0\alpha\Delta T\\ ={\rm100\: mm*25*10^{-6}\:\rm K^{-1}*55\: K}\\ =\rm0.014\: mm$$