fluids

when a tap-water is turned on slowly, the water flow is smooth but it looses its smoothness wen the speed of the outflow is increased ...

why?? [7]

13 Answers

62
Lokesh Verma ·

dont worry it is not in syllabus.. :)

You will study this in IIT that too if u are doing the fluid course :)

106
Asish Mahapatra ·

but still a brief reason?

1
Anurag Khandelwal ·

I think its because initially, the water flow isn't turbulent (determined by Reynold's constant) and it follows ideal fluid laws, but if the velocity of water flow is increased, flow becomes turbulent and the ideal fluid laws fail to describe and predict its motion...

1
skygirl ·

no ... but last year we had a this kinda question ...

not exactly this but somewhere near ... one min i will post it ..

1
skygirl ·

STATEMENT-1
The stream of water flowing at high speed from a garden hose pipe tends to spread like a fountain when held vertically
up, but tends to narrow down when held vertically down.
and
STATEMENT-2
In any steady flow of an incompressible fluid, the volume flow rate of the fluid remains constant.
(A) STATEMENT-1 is True, STATEMENT-2 is True; STATEMENT-2 is a correct explanation for STATEMENT-1
(B) STATEMENT-1 is True, STATEMENT-2 is True; STATEMENT-2 is NOT a correct explanation for
STATEMENT-1
(C) STATEMENT -1 is True, STATEMENT-2 is False
(D) STATEMENT -1 is False, STATEMENT-2 is True

62
Lokesh Verma ·

this is kind of different..

here you have to use continuity equation..

106
Asish Mahapatra ·

ya i think dis was in JEE'08
is the ans (A)

1
skygirl ·

does here gravity effect the velocity??

so moving up vel decreases so water spreads ??

something like this??

i got explanation no where..

fjee as always jus wrote the ans ...

so plz explain.. ne1...

62
Lokesh Verma ·

here simply use bernaulli's principle..

that is all :)

106
Asish Mahapatra ·

i think, as eqn of continuity,
when the liquid is projected upwards, its velocity reduces due to downward attraction of gravity. hence the area increases.
when the liquid is projected downwards, its velocity increases so, its area of cross-section decreases.
This explains the statement.

But wat is the ans sky of the A & R?

1
skygirl ·

ok got thanx bhaiya :)

1
skygirl ·

@ashish .. ans is A ..

106
Asish Mahapatra ·

ya statmen 2 explains 1 as stmnt 2 is basically just eqn of continuity

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