Ex$.1$

$130$

A Pitot$-$static tube is mounted on a Cessna $172$ to measure the

aircraft speed. The Pitot tube is attached to a manometer containing

mercury $($density $848\mathrm{.}3lb\frac{m}{f}{t}^3).$ The aircraft is cruising at an

altitude of $6,000ft.$ The manometer reads a pressure difference of

$0\mathrm{.}4$ in of mercury. Assuming standard atmosphere properties for air,

calculate:

a$)$ the aircraft speed, in kn $($knots$)$;

b$)$ the stagnation pressure, in psi.