IIT JEE , AIEEE Forum - Physics , Mechanics

sooraj

according to eqn of continuity,

the volume of water poured out at any position of a water tap must be constant.

then, why is it not so.

catch_arnnie

maybe becoz the flow is turbulent in nature....(i not 100% sure)...

sooraj

i also thought it to be so.
but when we just open the tap, the flow is streamline.
what abt that.

catch_arnnie

how do you know its a streamlined flow (as far as the normal taps are concerned, not the fancy ones or modern ones) ???

sooraj

when the tap is just open, there is free flow without disturbance.
itz streamline flow.

the falling water become turbulent when the velocity of water crosses the critical velocity due to gravity.

amangem

yes it is ...

watch carefully the lower part has lesser radius . but more velocity by bernoullis principle . hence the product av=constant

sooraj

yes, its true. then, the volume of water pouring out of the tap at any position must be a constant, but it is not so. why?

krishna.gopal

The equation of continuty says that for any position of tap the volume flow rate of water is constant through out the pipe. Thus if for a given position it is 100ml per minute it will be same at all points in the pipe and for another position it may be 150ml per minute again for all positions of pipe. But it does not says that if in first position the flow rate was 100 ml per minute, it will remain so in second position as well

sooraj

great answer . thank u sir

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