What is the gauge pressure at the bottom of the cylinder?

Question

Oil = 0.88m
P oil = 790kg
Brine = 1.11m
P brine = 1,025 kg

Answer 1

To find the gauge pressure at the bottom of the cylinder, we need to know the height and density of the fluids we are considering.

For the oil:
Height of oil, h_oil = 0.88 m
Density of oil, ρ_oil = 790 kg/m^3

For the brine:
Height of brine, h_brine = 1.11 m
Density of brine, ρ_brine = 1,025 kg/m^3

First, let's calculate the pressure at the bottom of each fluid using the formula P_1 = P_0 + ρgh, where P_0 is the pressure at the surface, ρ is the density of the fluid, g is the acceleration due to gravity (approximately 9.8 m/s^2), and h is the height of the fluid.

For the oil:
P_oil = P_0 + ρ_oil * g * h_oil

For the brine:
P_brine = P_0 + ρ_brine * g * h_brine

However, since the gauge pressure is the pressure relative to atmospheric pressure, we need to subtract atmospheric pressure from the calculated pressures. We will assume the atmospheric pressure is approximately 101,325 Pa.

Let's calculate the gauge pressure for each fluid.

For the oil:
Gauge pressure of oil = P_oil - 101,325 Pa

For the brine:
Gauge pressure of brine = P_brine - 101,325 Pa

Note: The gauge pressure will be negative if the pressure in the fluid is less than atmospheric pressure.

Please provide the value for P_0, the pressure at the surface, to calculate the gauge pressures accurately.