Fluids bernoulli's equation problem

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Homework Help Overview

The problem involves fluid dynamics, specifically applying Bernoulli's equation to a scenario with two horizontal tubes of different diameters. The original poster seeks to understand the relationship between pressure and flow speed in these tubes, given a pressure difference.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning

Approaches and Questions Raised

  • The original poster attempts to solve for flow speeds without knowing initial velocities. Some participants suggest focusing on qualitative aspects before quantitative analysis. Others propose using dummy variables for pressures to establish relationships between speeds and pressures in the tubes.

Discussion Status

The discussion is ongoing, with participants exploring different aspects of the problem. There is a suggestion to set up equations based on assumed pressures, which may lead to a clearer path for finding the unknown velocities.

Contextual Notes

Participants are navigating the constraints of not having specific velocity values and are discussing the implications of pressure differences in relation to fluid speed.

fishingaddictr
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Water flows throgh a horizontal tube of diameter 2.8cm that is joined to a second horizontal tube of diameter 1.6cm. the pressure difference between the tubes is 7.5kPa. which tube has the higher pressure flow? which tube has the higher speed flow? find the speed of flow in the first tube.

P2=p1+ (1/2)density(rho)(v1^2-v2^2)

how can i solve without a velocity 1 or 2?
 
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Without worrying about numbers (quantitative parts) -- can you first answer the qualitative parts?
 
pressure is greater in the bigger area with less fluid speed. the greater fluid speed has the least pressure.
 
Okay -- now say you KNOW the pressure in each part -- just call them dummy variables say P_b and P_s for the big and small diameter tubes. Can you then individually know the speeds in the tubes as functions of P_b and P_s? then you know the difference between P_b and P_s. Try setting up those... Then you might have as many equations as unknowns ands be able to solve for all your unknowns, including the velocity you want.
 

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