Question

pressure A vertical piston cylinder device contains a gas at an unknown pressure. If the outside pressure is 100 kPa, determine (a) the pressure of the gas if the piston has an area of 0.2 m2 and a mass of 20kg. Assume g = 9.81 m/s2. (b) What-if Scenario: What would the pressure be if the orientation of the device were changed and it were now upside down

Answer 1

Answer:

Explanation:

When Cylinder is vertical Let gas pressure inside is $P_1$ and atmospheric Pressure be

$P_0=100 KPa$

Area of Piston $A=0.2 m^2$

mass of Piston $m=20 kg$

from FBD

$mg+P_0A=P_1A$

$P_1=P_0+\frac{mg}{A}$

$P_1=100+\frac{20\times 9.8}{0.2}$

$P_1=100+0.98$

$P_1=100.98 KPa$

(b)If cylinder is upside down

From FBD

$mg+P_2A=P_0A$

$P_2=-\frac{mg}{A}+P_0$

$P_2=100-\frac{20\times 9.8}{0.2}$

$P_2=100-0.98=99.02 KPa$