Two rectangular plates, one of steel and the other of brass each $40mm$

wide and $10mm$ deep are placed together to form a beam $40mm20mm.$ Which is simply supported

at ends and having span of $1000mm.$ The brass plate being on the top of the steel plate. Determine the

maximum load which can be applied at the centre of the beam, if the plates are

$($i$)$ put one over other

$($ii$)$ firmly secured throughout their length

Maximum allowable stress in steel $=112\mathrm{.}5\frac{N}{m}{m}^2$ and in brass $=75\frac{N}{m}{m}^2.$ Take $E_s=200$GPa,