Why didn't Bernoulli's equation work for other values of water height?

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Homework Help Overview

The discussion revolves around the application of Bernoulli's equation in a fluid dynamics context, specifically regarding the flow of water from a tank through a hose at varying heights. The original poster presents a scenario involving a tank of water with compressed air and seeks to understand discrepancies in results when applying Bernoulli's equation at different water heights.

Discussion Character

  • Exploratory, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • The original poster attempts to apply Bernoulli's equation to calculate the speed of water flow at different heights but encounters issues with parts b and c. Some participants question the details of the calculations and suggest that unit conversion might be a factor. Others express a need for clarification on the procedure used.

Discussion Status

The discussion is ongoing, with participants exploring potential reasons for the original poster's difficulties. There is an indication that some guidance has been offered regarding the need for more details about the calculations. The original poster has mentioned a realization about reorganizing the Bernoulli equation, suggesting a potential shift in understanding.

Contextual Notes

There is a lack of detailed information regarding the calculations performed for parts b and c, which may be contributing to the confusion. The original poster's mention of using the same procedure raises questions about the assumptions made in the application of Bernoulli's equation.

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A large tank of water has a hose connected to it. The tank is sealed at the top and has compressed air between the water surface and the top. When the water height h has the value 3.5 m , the absolute pressure p of the compressed air is 4.20 * 10^5 Pa. Assume that the air above the water expands at cosntant temperature, and take the atmospheric pressure to be 1.0 * 10^5 Pa. a) What is the speed with which water flows out of the hose when h = 3.50 m? b) and c) just give other values to plugs in for the height. Now the question I have is: Can't i just use Bernouilli's equation? On the first one i did and got the right answer, but on part b and c i didn't, so what is the problem?
 
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Perhaps if you gave more details of what you did for parts b and c we could help you. Your troubles could simply be unit conversion how could we know when we do not have enough information.
 
Basically all i did was to plug the different heights in, the exact same place i did in part a), but i still got the wrong answer. Am i using the wrong procedure?
 
Any ideas fellas?
 
I could really use some help guys. If you have any ideas, they would be helpful.
 
Oh duh, I figured it out. Just had to reorganize the Bernouiili Equation.
 

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