Scenario $3.$ Rods $AB$ and $AC$ support load $P$ at $A,$ and are pin$-$connected at $B$ and $C.$ Rods $AB$ and $AC$ fail when their average normal stresses are $130$ and $155$MPa, respectively.

For $P=17kN$ and a safety factor of $3\mathrm{.}75,$ compute:

$[3-1$; $3$ marks$]$ the forces developed in the rods,

$[3-2$; $3$ marks$]$ the diameter of rod $AB,$ and

marks