Physics

Problem

A copper rod and an iron rod each have a length of

2\,\text{m}

20^{\circ}\text{C}

. Their coefficients of linear expansion are

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

for copper and

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

for iron. Both rods are heated uniformly to

70^{\circ}\text{C}

. Identify which rod experiences the greater increase in length and give a brief reason.