Question

A 72 inches aluminum wire is to be heated from 45 f to 150 f. By how much will it expand what will be its new length?

Answer 1

The linear thermal expansion is given by equation

$$\Delta l=l_0\alpha\Delta T$$

$$=72\:\rm in\times 13\times 10^{-6}\:\rm{1/F}\times (150-45)\:\rm F=0.098\:\rm in$$

The new length

$$l=l_0+\Delta l=72\:\rm in+0.098\:\rm in=72.098\:\rm in$$