A 2.4000 m long metal rod is composed of (welded) 0.9000 m long iron rod, 0.8000 m long copper rod, and 0.7000 m long aluminum rod measured at 10 °C.
Calculate the new length of the rod if the temperature is increased by 300 K.
What is the new length if the rod is cooled by 100 K?
The linear expansivities of iron, copper, and aluminium are 
, 
and 
respectively.
Calculate the results to 4 decimal places.
