Question

A steel railroad track has a length of 21 m
when the temperature is 2◦C.
What is the increase in the length of the
rail on a hot day when the temperature is
40 ◦C? The linear expansion coefficient of
steel is 11 × 10−6
(
◦C)−1
.
Answer in units of m.

Answer 1

$$ΔL=αLΔT$$

$$ΔL=(11⋅10 ^{−6} )(21)(40−2)=0.0088 m$$