Consider a bucket of water with two holes of equal area through which water is discharged. The water can flow out through hole ( B ), at the bottom, or through the down-spout, which begins at the top ( T ) and has its opening the same distance below the water level as the center of hole ( B).

  \-------------------------/
   \                       /
    \                     /__
     \                  T/--+|
      \                 /   ||
       \               /    ||
    ____\             /     ||
    -----\B          /      ||
          \---------/

Ignoring any friction effects, out of which opening will the water flow faster, and why?

(In reply to well well... by Art M)

What happens if I cut off the pipe at B?  Will the water then also change its state in being in free fall and flow faster?

And I am afraid that, U turn or not, the flow rate will increase once the long pipe is filled.  Just look at the forces at the exits of the pipes: what you call the free falling water is the same as the hydrostatic pressure delivered by the water above the exit level.
Pipe length, specific weighte and gravity. that's all there is.

To Larry: in the text, the problem says that the the T outlet is at the center of B.  That's why I made the remark about atmospheric pressure vs altitude is a non linear function.

 

Posted by Hugo on 2006-09-29 12:44:52