Pressure block/diagram in hydraulics

[Stacyg]

a) Calculate using stress (or pressure) block method, the total force on the side of a tank that is 4m wide and 5.4m deep and contains sea water of specific gravity 1.025.
b) If a 1.20m depth of oil of specific gravity 0.85 was added to the sea water in part a above, draw the new pressure diagram and calculate the pressure at the base of the tank.

I've done part a of the question and have calculated the pressure at the bottom of the tank to be 54.3kpa and the force to be 586.4kN.
But I'm not sure how to do B. Do I calculate the pressure of the oil as it's on top of the sea water and add the two pressures together to get the pressure at the bottom and calculate the force from there?? I have another question similar to this with a layer of oil on top of a layer of seawater, would this be done the same way?

Thanks

 

[Valkarie]

in advance.Yes, you are correct. To calculate the pressure at the base of the tank, you need to add the pressure of the oil (calculated using the stress block method) to the pressure of the seawater (also calculated using the stress block method). Once you have calculated the total pressure at the base of the tank, you can then calculate the total force on the side of the tank.

 

[piercas]

for your question. In order to answer part b of the question, we first need to understand the concept of pressure in hydraulics. Pressure in hydraulics is defined as the force per unit area exerted by a fluid. In this case, the fluid is a combination of seawater and oil.

To calculate the pressure at the base of the tank, we need to consider the pressure exerted by both the seawater and the oil. Since the oil is on top of the seawater, it will add an additional pressure to the existing pressure of the seawater.

To calculate the pressure of the oil, we can use the same formula as in part a, but with the specific gravity of oil (0.85) instead of seawater (1.025). This will give us the pressure exerted by the oil on top of the seawater.

Next, we can add the pressure of the oil to the pressure of the seawater to get the total pressure at the base of the tank. This will give us the new pressure diagram.

To calculate the force at the base of the tank, we can use the same formula as in part a, but with the new total pressure. This will give us the new force exerted on the side of the tank.

For the second question with a layer of oil on top of a layer of seawater, the process would be the same. We would calculate the pressure and force of each layer separately and then add them together to get the total pressure and force at the bottom of the tank.

I hope this helps clarify the process for you. If you have any further questions, please don't hesitate to ask.