How Does Nozzle Elevation Affect Water Flow and Pressure in a Hose System?

[asheik234]

Homework Statement

Consider a hose that carries water (density = 1000 kg/m3) leads to a nozzle that is elevated h = 1.3 meters above the ground. The nozzle has a diameter d, and the hose has a diameter D = 5d. Water flows through the hose with a speed vH = 0.6 m/s.

(a) What is the speed of the water as it leaves the nozzle?


(b) What is the gauge pressure of the water in the hose at ground level?

Homework Equations

P+pgh+(1/2)pV^2 = P+pgh+(1/2)pV^2
Area * V = Area * V

The Attempt at a Solution

I'm confused on the part where the hose is elevated upward, I know the velocity decreases, but I don't know by how much.

 

[gneill]

Is water compressible or incompressible? What does that imply for the flow rate at any point along the (constant diameter) hose?

 

[asheik234]

It is compressible, does that mean it stays the same throughout?

 

[gneill]

It is compressible, does that mean it stays the same throughout?

Are you guessing? If water is compressible, why can't we store a cubic meter of water in a one liter container?

For all practical purposes, water is NOT compressible. So for a filled, constant diameter pipe, the flow rate must be the same everywhere -- otherwise, wouldn't water "pile up" behind the slow regions and "thin out" in the speedy ones?