Eor Nos $18-19$: A column of length $L$ is sitting on a rigid floor as shown in the figure. At installation time there is a gap d between the top of the column and the rigid ceiling above. The distance between ceiling and floor is constant for the purpose of this problem. $)=3\mathrm{.}5(m)$;$d=1\mathrm{.}2(mm)$;$,a=1310\frac{}{C}$;$E=(205$GPa

By how much must the temperature of the column rise in order for the gap $d$ to close?

$($a$)26\mathrm{.}37C$

$($b$)23\mathrm{.}63C$

$($c$)133\mathrm{.}25C$

The normal stress in the column at a temperature $50C$ above that at installation time is $q,$ MPa.

$($d$)62\mathrm{.}960$

$($a$)26\mathrm{.}37$

$($b$)23\mathrm{.}63$

$($c$)133\mathrm{.}25$

$($d$)62\mathrm{.}96$