Physics

Problem

A square aluminium plate has an area of

0.25\,\text{m}^2

20^{\circ}\text{C}

. The coefficient of linear expansion of aluminium is

2.4\times10^{-5}\,\text{K}^{-1}

. Find the increase in its area when the temperature is raised to

70^{\circ}\text{C}

, using the usual approximation relating β and α.