Answer to Question #234068 in Mechanical Engineering for Randal Rodriguez

Question

4. What is the pressure (psia) at the base of a 8 ft liquid column with atmospheric pressure 755 mm Hg, if

the fluid is a) water, b) glycerin (SG = 1.25), c) Oil (SG = 0.750)

Answer 1

$P =P_{\text{atm}}+\rho gh$

$P_{\text{atm}} =\dfrac{755\text{ mmHg}}{760\text{ mmHg}}× 101325\ Pa$

$=100658 Pa$

$h = 8\ ft= 2.44\ m$

a) $P =P_{\text{atm}}+\rho gh\\ P = 100658 + 1000(9.8)(2.44) = 124570\ Pa$$P =P_{\text{atm}}+\rho gh\\ P = 100658 + 1000(9.8)(2.44)(1.25) =\\$

b)$P =P_{\text{atm}}+\rho gh\\ P = 100658 + 1000(9.8)(2.44)(1.25)\\= 130548 \ Pa$

c)

$P =P_{\text{atm}}+\rho gh\\ P = 100658 + 1000(9.8)(2.44)(0.75)\\ = 118592 \ Pa$