Velocity of water in water hose

[foo9008]

Homework Statement

in this problem , the author assume that velocity inside the hose is very low , near to 0 . but , it's not stated in the question , it's the anaylsis of the author . How do we know that the velocity of water in hose is close to 0 , if it is not mentioned earlier?

Homework Equations

The Attempt at a Solution

 

[billy_joule]

in this problem , the author assume that velocity inside the hose is very low , near to 0 . but , it's not stated in the question , it's the anaylsis of the author . How do we know that the velocity of water in hose is close to 0 , if it is not mentioned earlier?

Because the question implies it. Draw a diagram and it should show itself.

 

[foo9008]

Because the question implies it. Draw a diagram and it should show itself.

i still don't understand , can you explain ?

 

[billy_joule]

The question states the hose is mainly closed and only a thin jet remains. Apply the continuity equation, if the jet outlet area is much smaller than the hose area then velocity in the hose must be close to zero.