Question

A steel beam is used in the construction of a skyscraper. By what fraction L/L_o does the length of the beam increase when the temperature changes from that on a cold winter day (–15 °F) to that on a summer day (+105 °F)?

Answer 1

This ratio is

$$\frac{L_S}{L_W}=\frac{1+\alpha T_S}{1+\alpha T_W},\\\space\\ \frac{L_S}{L_W}=\frac{1+0.0000061·105}{1+0.0000061 ·(-15)}=1.0007.$$