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?

This great physicist created a TV Series called "Why Is It So?" during the 3rd quarter of the last century (true C20.) on visits to Australia, a set of books were published which reflected many or all of what he discussed.

Can't find the books, but I believe he had a problem which asked to determine the visual trajectory of the simultaneous flows of water from three cleanly bored holes which were spaced at 1/4, 1/2 and 3/4 distant from the top of a fruit tin (the water level at the top of the can was kept constant).

The trajectories were NOT as many student physic books illustrated.

The experiment does not answer the question, but .... I believe that the principle is very much in line with Leming's explanation.

I'm thinking, like Hugo, that the greater the depth, the more pressure is exerted which should mean higher lower flows and an initially flatter declining parabolic curve than a higher exit.

Posted by brianjn on 2006-09-29 05:02:06