Find difference in pressure in this water intake pump

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Homework Help Overview

The problem involves calculating the difference in pressure between the inlet and outlet of a water intake pump using Bernoulli's Equation. The scenario includes parameters such as cross-sectional areas, flow speeds, and a vertical distance between the two points.

Discussion Character

  • Exploratory, Assumption checking, Mathematical reasoning

Approaches and Questions Raised

  • The original poster attempts to apply Bernoulli's Equation to find the pressure difference but expresses uncertainty about their calculations and conversions. Some participants question the conversion from atm to MPa and suggest focusing on converting directly from Pa to MPa.

Discussion Status

Participants are actively discussing the correctness of the original poster's analysis and calculations. There is a focus on the conversion of units, with some guidance provided regarding the appropriate conversions to use.

Contextual Notes

There are indications of potential confusion regarding unit conversions and the application of Bernoulli's Equation. The original poster seems to be grappling with the setup of the problem and the implications of their calculations.

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A water intake at a pump storage reservoir (Fig. 14-44) has a cross-sectional area of 0.87 m2. The water flows in at a speed of 0.35 m/s. At the generator building, at distance D = 180 m below the intake point, the cross-sectional area is smaller than at the intake and the water flows out at 9.8 m/s. What is the difference in pressure, in megapascals, between inlet and outlet?

Im using Burnoulli's Equation:

P1 -P2 = density(g)(Y1- Y2) + 1/2 (density)(V2^2 - V1^2)
density of water = 1000
so = (1000)(9.8)(180) + 1/2(1000)(9.8^2 - 0.35^2)
= 1811958.75Pa/1.01x10^5Pa
= 17.94 atm

But then answer is in MPa, So then i get 1.794 x10^-6 MPa

But that is not correct, is the analysis i made incorrect? I think i am missing something key in the problem. Thanks in advance.
 
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Without looking at your problem set up your conversion from atm to MPa is incorrect. 17.9 atm = 1.81 MPa.
 
Why did you convert from Pa to atm? Just convert Pa to MPa.
 
to be honest, I am not sure i did. silly.

but is the analysis i did correct for the problem?
 


Did he do the question correct?
 

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