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

$$ΔL=αLΔT$$

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