flud for the threc$-$dimensional case.

$2\mathrm{.}2.$ The container of Fig. $2\mathrm{.}44$ holds water and air as shown. What is the

pressure at $A,B,C,$ and $D$ in pounds per square foot?

$2\mathrm{.}3.$ The tube in Fig. $2\mathrm{.}45$ is flled with oll. Determine the pressure at A and

$B$ in feet of water.

FLUID STATICS

$2\mathrm{.}4.$ Calculate the pressure at $A,B,C,$ and $D$ of Fig. $2\mathrm{.}46$ in pounds per square

inch.

$2\mathrm{.}5.$ Derive the law of variation of static pressure for an incompressible fluid

by considering a free body of fluid that is an inclined right circular cylinder.

$2\mathrm{.}6.$ Derive the equations that give the pressure and density at any elevation

in a static gas when conditions are known at one elevation and the temperature

gradient $$ is known.

$2\mathrm{.}7.$ By a limiting process as $0,$ derive the isothermal case from the results

of Prob. $2\mathrm{.}6.$

$2\mathrm{.}8.$ By use of the results of Prob. $2\mathrm{.}6,$ determine the pressure and density at

$5000-$ft elevation when $p=14\mathrm{.}5a,t=68F,$ and $=-0\mathrm{.}003\frac{F}{f}t$ at eleva$-$

tion $1000$ ft for air.

$2\mathrm{.}9.$ For isothermal air at $40F,$ determine the pressure and density at $10,000ft$

when the pressure is $15$ psia at sea level.

$2\mathrm{.}10.$ In isothermal air at $60F$ what is the vertical distance for reduction of

density by $10$ per cent?

$2\mathrm{.}11.$ Express a pressure of $5$ psi in: $($a$)$ inches of mercury, $($b$)$ feet of water, $($c$)$

feet of acetylene tetrabromide, sp gr $2\mathrm{.}94.$

$2\mathrm{.}12.$ A bourdon gage reads $2-$psi suction, and the barometer is $29\mathrm{.}5$ in $.$ mer$-$

cury. Express the pressure in six other customary ways.

$2\mathrm{.}13.$ Express $3$ atmospheres in feet of water gage. Barometer reading

$29\mathrm{.}2$ in$.$

$2\mathrm{.}14.$ Bourdon gage A inside a pressure tank reads $10$ psi $.$ Another bourdon

gage $B$ outside the pressure tank, connected with the tank, reads $18$ psi $,$ and an

aneroid barometer reads $30$ in $.$ mercury. What is the absolute pressure measured

by $A$ in inches of mercury?

$2\mathrm{.}15.$ Determine the heights of columns of water; kerosene, $spgr0\mathrm{.}83$; and

acetylene tetrabromide, sp gr $2\mathrm{.}94,$ equivalent to $10$ in $.$ mercury.

$2\mathrm{.}16.$ For a reading $h=16in.$ in Fig. $2\mathrm{.}8$a determine the pressure at $A$ in

pounds per square inch. The liquid has a specific gravity of $1\mathrm{.}90.$

$2\mathrm{.}17.$ Determine the reading $h$ in Fig. $2\mathrm{.}8b$ for $p_A=2\mathrm{.}5$ psi suction if the liquid

is kerosene, sp gr $0\mathrm{.}83$

$2\mathrm{.}18.$ For $h=6in.$ in Fig. $2\mathrm{.}8b$ and barometer reading $29$ in $.,$ with water the

liquid, find $p_A$ in feet of water absolute$.$

$2\mathrm{.}19.$ In Fig. $2\mathrm{.}8c{S}_1=0\mathrm{.}86,S_2=1\mathrm{.}0,h_2=8\mathrm{.}3$ in$.,h_1=17in.$ Find $p_4$ in