Bernoulli's principle- fluids ?

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Homework Help Overview

The discussion revolves around Bernoulli's principle in fluid dynamics, focusing on the application of the principle to a specific problem involving fluid flow and pressure relationships. Participants are exploring the equations related to fluid motion and pressure changes.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning, Problem interpretation

Approaches and Questions Raised

  • Participants are attempting to manipulate Bernoulli's equation and related formulas to solve for unknown variables. Questions arise regarding the correctness of the equations being used and the implications of canceling terms in their calculations.

Discussion Status

Some participants are actively engaging with the problem, sharing their attempts and expressing frustration over their progress. Guidance has been offered regarding the formulation of the velocity term and the cancellation of pressure values, indicating a productive direction in the discussion.

Contextual Notes

There appears to be some confusion regarding the application of Bernoulli's equation and the specific conditions of the problem, such as the ambient pressure values and the need for velocity information, which are under discussion.

A_Munk3y
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bernoulli's principle- fluids...?

Homework Statement



http://img30.imageshack.us/img30/4119/45086777.jpg

Homework Equations



A1V1=A2V2
P2+1/2pv1^2 = p1+1/2pv2^2
P+1/2mv^2 + pgy = constant

The Attempt at a Solution



V2=A1*V1/A2
1/2*p*A1^2*V1^2*p*g*h/A2^2=1/2pv1^2
2*g*h*A1^2V1^2/ A2^2=V1^2
V1=A1*V1gh/A2and I am stuck... i end up canceling the V1 >:(
 
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GOOOOD!
i've tried like 10 different things and i can't get it..
 


Do you think this equation correct? "P2+1/2pv1^2 = p1+1/2pv2^2"

ehild
 


Write out your full Bernoulli's equation:
<br /> P + \frac{\rho V^2}{2} + \rho g z = c<br />
The pressure values are both places are ambient so they cancel. You have the change in distance z2 - z1, so the only thing left is to find the velocity. Unfortunately, you don't have this.

So, it will be useful to write our your velocity term as a function of mass flow and area. You know that mass flow is equal, so you will eventually be left with simply area.
 


i got it!
thanks ! :D
 

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