At room temperature, a $0\mathrm{.}6-mm$ gap exists between the ends of the rods as shown in Figure Q$2($a$).$ At a later time when the temperature has increased by $120$ degree Celsius, determine the followings:

$\backslash$table$[[$Aluminum$,$Stainless steel$],[A=2000m{m}^2,A=800m{m}^2$