A rigid bar ABCD is supported by two bars as shown. There is no strain in the vertical bars before load $P$ is applied. After load $P$ is

applied, the normal strain in $\frac{?}{\text{b}\text{a}\text{r}}(1)$ is $-730\frac{m}{m}.$ Assume $a=280mm,b=360mm,c=100mm,L_1=900mm,$ and $L_2=1400mm.$

Determine:

$($a$)$ the normal strain in bar $(2).$

$($b$)$ the normal strain in bar $(2)$ if there is a $1-$mm gap in the connection at pin $C$ before the load is applied.

$($c$)$ the normal strain in bar $(2)$ if there is a $1-$mm gap in the connection at pin $B$ before the load is applied.