A straight rod comprises of a 2 cm length of aluminum joined to the other length of steel. The length of full rod changes by 16.4 µm if its temperature rises from 20°C to 40° C.
Determine the initial length of the steel component of the straight rod. The coefficient of linear expansion are 23 x 10^-6 K^-1 for aluminum and 12 x 10^-6 K^-1 for steel.