What must the water pressure be to supply water to the third flor of a buiking 35.0 ft up with a pressure of 40.0 lb/in(2) at that level? I have the answer,but I need to know how to get the answer. thanks
Find required water pressure to supply water at h = 35.0 ft and P = 40.0 Lb/in^2.
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Working equation: P = hDw where
P = pressure, h = height, Dw = weight density (Dw for water is 62.4 Lb/ft^2)
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P at bottom = hDw = (35.0 ft)(62.4 Lb/ft^3) = 2184 Lb/ft^2
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Convert to Lb/in^2 to match question: 2184 Lb/[ ft^2(144 in^2/ft^2)] = 15.2 Lb/in^2
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We want 40.0 Lb/in^2. To this we add (P)ressure just calculated above:
Pressure required = 40.0 Lb/in^2 + 15.2 Lb/in^2 = 55.2 Lb/in^2.
Find the weight of a column of water A in area, h high.
weight= densitywater*g*area*height
but pressure= weight/area= density*g*h
but one wants an additional 40psi, so that has to be added..
pressure=density*g*h+ 40lbs/in^2*
so solve. Watch units. I would work it in English, density*g= 0.0361273lbs/in^3
h= 35ft= 35*12inches
Well, to calculate the water pressure needed to supply water to the third floor, we need to consider the height difference and the pressure at that level.
Firstly, we need to convert the height from feet to inches because the pressure is given in pounds per square inch (lb/in²). So, 35.0 ft is equal to 35.0 ft × 12 in/ft = 420.0 inches.
Now, we can calculate the water pressure using the following formula:
Pressure = Density × Gravity × Height
Where:
- Density is the density of water, which is approximately 62.4 lb/ft³.
- Gravity is the acceleration due to gravity, which is approximately 32.2 ft/s².
- Height is the height difference, which is 420.0 inches in this case.
Using these values, we can calculate:
Pressure = 62.4 lb/ft³ × 32.2 ft/s² × 420.0 in ÷ 12 in/ft ≈ 188382.0 lb/in²
So, the water pressure needed to supply water to the third floor would be approximately 188382.0 lb/in².
Now remember, this is just a hypothetical calculation using the given formula. In reality, the water pressure required may differ depending on various factors and the design of the building. So, don't start installing a clown-sized water pump just yet!
To determine the water pressure required to supply water to the third floor of a building, you need to consider the elevation difference and the conversion from feet to pounds per square inch (lb/in²).
First, calculate the elevation difference between the water source and the third floor. In this case, the building is 35.0 ft tall.
Next, convert the elevation difference from feet to inches. Since there are 12 inches in a foot, multiply the elevation by 12 inches/foot.
35.0 ft × 12 in/ft = 420.0 in
So, the elevation difference is 420.0 inches.
Finally, convert the pressure from lb/in² to inches of water (inH₂O). To do this, you need to know the conversion factor, which is approximately 27.68 inH₂O per lb/in².
Multiply the given pressure by the conversion factor:
40.0 lb/in² × 27.68 inH₂O/lb/in² = 1,107.2 inH₂O
The calculated value, 1,107.2 inH₂O, represents the water pressure required to supply water to the third floor of the building.