Question $1$

Bending Stresses

$1\mathrm{.}1$ Consider a $6$ m long simply supported beam with a cross section as shown in figure $3.$ The beam is subjected to a point load acting at mid distance downward. If the magnitude of the point load together with the beam weight is $8$ kN $,$ determine: the magnitude of the bending moment.

$1\mathrm{.}2$ An elevated platform is to be constructed to carry and uniform inclusive load of $10k\frac{N}{m^2}.$ The supporting beams are simply supported over a span of $6$ m and are to be spaced at $1\mathrm{.}5$ m intervals. From table $4$ select a suitable I section $($universal beams$)$ using an allowable stress of $120$ MPa $.$ What will the actual working stress be$?$

$(15)$

$[30]$