Chapter 6.8, Problem 31E

A steel railroad rail expands and contracts according to the formula $\Delta l=\alpha l\Delta T,$ where, $\Delta l$ is the change in length, $\alpha$ is a constant called the coefficient of linear expansion, l is the original length, and $\Delta$

T is the change in temperature. If a 50.0-ft steel rail is installed at $0°\text{F}$, how many inches will it expand when the temperature rises to $100°\text{F}$? $\alpha =\text{6}\text{.5}\times {\text{10}}^{-6}/°\text{F}$.