Find difference in pressure in this water intake pump

AI Thread Summary
The discussion focuses on calculating the pressure difference in a water intake pump using Bernoulli's Equation. The user initially calculates the pressure difference but incorrectly converts the final result from atm to MPa. It is clarified that the correct conversion is to directly convert from Pa to MPa, resulting in 1.81 MPa instead of the previously calculated 1.794 x 10^-6 MPa. The user is advised that their analysis is fundamentally correct, but the conversion error led to an incorrect final answer. Overall, the key takeaway is the importance of proper unit conversion in pressure calculations.
mb85
Messages
44
Reaction score
0
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.
 
Physics news on Phys.org
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?
 
Thread 'Voltmeter readings for this circuit with switches'
TL;DR Summary: I would like to know the voltmeter readings on the two resistors separately in the picture in the following cases , When one of the keys is closed When both of them are opened (Knowing that the battery has negligible internal resistance) My thoughts for the first case , one of them must be 12 volt while the other is 0 The second case we'll I think both voltmeter readings should be 12 volt since they are both parallel to the battery and they involve the key within what the...
Thread 'Correct statement about a reservoir with an outlet pipe'
The answer to this question is statements (ii) and (iv) are correct. (i) This is FALSE because the speed of water in the tap is greater than speed at the water surface (ii) I don't even understand this statement. What does the "seal" part have to do with water flowing out? Won't the water still flow out through the tap until the tank is empty whether the reservoir is sealed or not? (iii) In my opinion, this statement would be correct. Increasing the gravitational potential energy of the...
Back
Top