Fig. $1.$ for Question $1$

$2.$ Segments $AB$ and $CD$ of the assembly are solid circular rods, and segment $BC$ is a tube as shown

$[20]$

in Fig. $2.$ If the assembly is made of aluminum, determine the displacement of end $D$ with respect

$CO3$:$PO3$

to end $A.$ Assume $E_{al}=70$GPa.

Section $a-a$

Fig, $2.$ for Question $3$ :