Engineering Fluid mechanics question and the Bernoulli Equation

AI Thread Summary
The discussion revolves around solving fluid mechanics problems Q2 and Q3, specifically using the Bernoulli Equation. For Q2, there is confusion regarding the application of the formula P=Patm+qgh, with users noting that their calculated pressures exceed expected values. In Q3, it is clarified that the pressure at point 2 is not equal to that at point 1 due to the velocity increase in the pipe, leading to lower pressure at point 2. Participants express frustration over the computer's inability to recognize correct units and urge for clearer question presentation. The conversation highlights the complexities of applying Bernoulli's principles in practical scenarios.
Franklie001
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Homework Statement
Fluid mechanics question and Bernoulli Equation
Relevant Equations
Q2 and Q3
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Good afternoon,

I am struggling to find the solution at Q2 and Q3. For Q2 the absolute pressure at point 1 is at the bottom of the tank, so do i need to use the formula P=Patm+qgh ? If using this formula I've got a bigger number than 100Pa.
Same issue for Q3, isn't the pressure at point 2 equal the one at point 1, being at the same height? The question mention that the answer should be within 500 Pa.

Thank you
 

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Franklie001 said:
I am struggling to find the solution at Q2 and Q3
I suppose Q2 is in the first picture ?
I find it a struggle to even read the questions in the second picture. Can you type them out ? At least Q3 ?

Franklie001 said:
If using this formula I've got a bigger number than 100Pa
Yes, 105 + ##\rho g \Delta h\ ## is a lot more than 100. Is your answer not accepted ? I get the same. I resent that the dumb computer doesn't see units.

I also get the same for Q1 (almost :smile:: 16.27 kg/s)

Please post your work.

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The pressure at point 2 is not equal to the pressure at point 1. At point 2 (immediately inside the pipe) the velocity has built up in the approach to to the pipe (within the tank) from zero at point 1 (and other locations at the bottom significantly removed from the pipe entrance) to full pipe velocity at point 2. So the pressure at point 2 is significantly lower than at point 1.
 
Hello Chet ! You apparently have been able to read Q3. But OP asks about Q2 (which is legible) as well.

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