Question

If the local atmospheric pressure is 14.6 psia, find the absolute pressure (in psia) in a column of glycerin (rho = 74.9 lbm/ft^3) at depth of 27in.

Answer 1

52.2538 psia

Step-by-step explanation:

The absolute pressure at depth of 27 inches can be calculated by:

Pressure = Local pressure + Gauge pressure

Also,

`P_(gauge)=\rho* g* h`

Where,

`\rho` is the density of glycerin (
`\rho=74.9\ lbm/ft^3`)

g is the gravitational acceleration = 32.1741 ft/s²

h = 27 in

Also, 1 in = 1/12 ft

So,

h = 27 / 12 ft = 2.25 ft

So,

`P_(gauge)=74.9* 32.1741* 2.25\ lbf/ft^2=5422.1402\ lbf/ft^2`

Also,

1 ft = 12 inch

1 ft² = 144 in²

So,

`P_(gauge)=5422.1402\ lbf/ft^2=\frac {5422.1402\ lbf}{144\ in^2}=37.6538\ lbf/in^2=37.6538\ psia`

Local pressure = 14.6 psia

So,

Absolute pressure = 14.6 psia + 37.6538 psia=52.2538 psia