OUESTION $5[20$ MARKS$]$

$($a$)$ A $90$ elbow is attached to DN$50(2$ in$)$ Schedule $40$ pipes carrying kerosene $(25C)$ at $0\mathrm{.}092\frac{m^3}{s}.$ Calculate the resultant force required in the pipe.

$[8$ Marks$]$

$($b$)$ Figure $5$ shows the truck with deflector on top of the truck. The aerodynamic drag on a truck can be reduced by the use of appropriate air deflectors with $C_d=0\mathrm{.}70.$ Drag coefficient without deflector is $0\mathrm{.}95.$ Height of front truck is $350cm$ and width $300cm.$ Compare the differences of power needed at a highway speed of $90k\frac{m}{h}$ at temperature $30C.$

Figure $5$: A truck

$[12$ Marks$]$

$-$END OF QUESTION PAPER$-$