Two solid cylindrical rods $AB$ and $BC$ are welded together at $B$ and loaded as shown.

Determine the average normal stress at the midsection of :

$(a)rodAB$

$($b$)$ rodBC

$($c$)$determine the new magnitude of force P for which the stresses in the rodAB and BC are the same magnitud

$($d$)$ if the direction of force $P$ is changed as compressive force, evaluate what will be happened of the average normal stress at AB and BC $.$

ANSWER $[($a$)81\mathrm{.}5$ MPa, $($b$)-18\mathrm{.}11$ MPa, $($c$)73\mathrm{.}83$ kN $]$

THIS IS STRENGTH OF MATERAIL SUBJECT MECHANICAL ENGINEERING $.$

NOTE:PLEASE DRAW A FREE BODY DIAGRAM WHEN YOU DO THIS QUESTION $.$

PLEASE WRITE ALL THE ANSWER INN PAPER $.$THANKS.