A steel section of the Alaskan pipeline had a length of 65 m and a temperature of 16°C when it was installed. What is its change in length when the temperature drops to a frigid -39°C?

Answer 1

The pipe shortens. That is a -55 C temperature change.

length change =
L*alpha*(delta T)
-(65 m)*(thermal expansion coefficient of steel)* (55 C)

Look up the thermal expansion coefficient of steel for that temperature range. It is about 12*10^-6 per degree C