Answer all the questions.

$(15$ marks$)$

Q$1.$ A typical rigid bar $AB$ of length $4m$ for a cantilever type car shed as shown in figure $A$ is hinged at B and supported in a horizontal position by $2$ inclined steel wires of diameter $3cm$ each is placed at a distance of $1m$ and $3m$ respectively from end $A.$

$5m$

rigure a

a$)$ Find safe load that can be applied at A$.$ Assume load factor of $1\mathrm{.}75.$ Take $f_K=460\frac{N}{m}{m}^2.$

b$)$ If end $B$ is now replaced with a fixed support and with a fixed end moment of $60kN-m.$ Find the Safe load that can be applied at joint A$.$