Solving Liquid Flow Problem: Speed in Lower Pipe

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The discussion revolves around solving a liquid flow problem using Bernoulli's Equation and the Continuity Equation. The user correctly identifies that since the pressure is the same in both pipes, it allows for simplification of Bernoulli's Equation. By setting the heights and applying the flow continuity principle, the user calculates the speed in the lower pipe to be 14.44 m/s. Other participants confirm the approach and calculations, affirming the correctness of the method used. The conversation highlights the importance of applying both Bernoulli's and Continuity Equations in fluid dynamics problems.
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"A liquid is flowing through a horizontal pipe whose radius is 0.10m. The pipe bends straight up for 10.0m and joins another horizontal pipe whose radius is 0.20m. It was found that the pressure in the lower pipe and the upper pipe were the same. What is the speed in the lower pipe? [An image shows this that the higher pipe is 10m above it."

I'm just checking if this is right, any help - thanks.

I used Bernoulli's Equation of
P_{1} + \frac{1}{2} \rho v_{1}^2 + \rho gy_{1} = P_{2} + \frac{1}{2} \rho v_{2}^2 + \rho gy_{2}
[Initial conditions = Final conditions, where P=pressure, v=velocity, \rho=density, and y=height]

Since it said "a liquid" i knew \rho=\rho, and the pressure is the same so P_{1}=P_{1}. So I removed Pressure from both sides, and removed \rho.

The new equation:

\frac{1}{2} v_{1}^2 + gy_{1} = \frac{1}{2} v_{2}^2 + gy_{2}

since y_{1} = 0, it becomes: \frac{1}{2}v_{1}^2 = \frac{1}{2}v_{2}^2 + (9.8)(10)

then I plugged that equation into Av_{1} = Av_{2} [area times velocity = area times velocity, 2equations-2unknowns.]

I solved for the first velocity getting 14.44m/s.


**Can anyone confirm if this is the right way? -Thanks in advance.
 
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Yes, this is what i got

\frac{1}{2}v_{2}^2 + gh = \frac{1}{2}v_{1}^2

For solving this you need the Flow Continuity equation

A_{1}v_{1} = A_{2}v_{2}

Just like you did

Good work! :smile:
 
Awsome, thank you so much. :approve:
 
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