Answer:
The gauge pressure of air is 110 kpa
Explanation:
Atmospheric pressure, [tex]P_{atm}[/tex] = 101 Kpa
[tex]P_{gauge} + \rho_w gh_1 + \rho_o gh_2 -\rho_{Hg} gh_3 =P_{atm}[/tex]
[tex]P_{gauge} = P_{atm} - \rho_w gh_1 - \rho_o gh_2 +\rho_{Hg} gh_3[/tex]
where;
ρw is the density of water = 1000 kg/m³
ρo is the density of oil = 800 kg/m³
ρHg is the density of mercury = 13,600 kg/m³
g is acceleration due to gravity = 9.8 m/s²
[tex]P_{gauge} = 101,000 - (1000* 9.8*0.2) - (800* 9.8*0.3) +(13,600* 9.8*0.46)\\\\P_{gauge} = 101,000 - 1960 - 2352 + 13610.26\\\\P_{gauge} = 110,298.26 pa[/tex]
Therefore, the gauge pressure of air is 110 kpa