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Nirupt

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## Homework Statement

For the pipe reducer shown in Figure 6.27 in your textbook, the pressure at point A is 45.8 psig and the pressure at B is 39.5 psig. Calculate the velocity of flow, in ft/s, of the water at point B.

State your answer to one decimal place. Example: 25.6

## Homework Equations

http://img28.imageshack.us/img28/4754/7m2c.png [Broken]

Which is the equation we are using, P is pressure, Z is height (which is 0 for both A, and B), g is 32.2 ft/s^2 and gamma (specific weight, is 62.4 lb/ft^3 I believe)

Image of the problem: http://img802.imageshack.us/img802/9700/byqt.jpg [Broken] Ignore the book problem as the numbers have been changed.

Remember to divide pressure by gamma

Remember to calculate velocities at points A and B Velocity = flow rate/Area

Elevation at point A is zero and Elevation at point B is zero

Do forget to take the square root to calculate the velocity

## The Attempt at a Solution

I know since B is a small tube the velocity at point B must be higher than point A. I have the answer outcome to be 31.6 ft/s but I'm not totally sure that is correct.

I have two unknowns though which is both velocities.. and it's confusing me because the only way to cope with that is the equation VaAa = VbAb which Velocity is V and Area is A, finding the area using the equation ∏*D

^{2}/4 I have converted in to ft and obtained both areas which are..

Aa = .0218 ft^3

Ab = .00545 ft^3

I have tried putting one unknown and plugging either velocity in for the other.. but it doesn't make sense to me. Plus the flow rate is not given, and I cannot find it because I have neither velocity numbers.. overall there appears to be 2 unknowns, flow RATE, and VelocityA, and we are solving for Velocity B.

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