Grade $50$

$P_L=50$kips

$P_D=30$kips

$P_{}=15$kips

$L_1=9ft$

$6(9)=54ft$

a$)$ Find the maximum fectored tension force that the bottom chord of the truss is expored to

b$)$ Find the lightest double L section to carry the tension lowed only at the bottom chord

c$)$ Calculate the capocity of the tension using equations $($yelding ans rupture only$)$ considermy welds as $10$ inch at the top and $5$ in at the bottom of $L$ shape.