Question

he coefficient of linear expansion of steel is 12 × 10-6 K-1 . What is the change in length of a 25-m steel bridge span when it undergoes a temperature change of 40 K from winter to Summer?

Answer 1

ΔL = 12 mm

Step-by-step explanation:

Given that

Coefficient of linear expansion ,α = 12 x 10⁻⁶ K⁻¹

Length of steel bridge ,Lo= 25 m

Change in the temperature ,ΔT = 40 K (Winter to summer)

It means that change in the temperature is positive.

We know that the change in the length given as

ΔL = Lo α ΔT

Now by putting the values

ΔL = Lo α ΔT

ΔL =25 x 12 x 10⁻⁶ x 40 m

ΔL =12000 x 10⁻⁶ m

ΔL =12 x 10⁻³ m ( 1 mm =10⁻³ m )

ΔL = 12 mm

Therefore the change in the length of the bridge

ΔL = 12 mm