What is the shape of an hour-glass with the following characteristics:
1)it will be used with water, not sand
2)two identical glass shapes are fused with a tiny hole connecting them and adequate venting to prevent any changes in air pressure from impeding water flow
3)the rate of flow through the hole between the top and bottom portion is proportional to water pressure
4)the horizontal cross section of the hourglass is a circle at every level, and it is symmetric around a vertical axis
5)the water level is proportional to the time elapsed

(In reply to Problem with question by hoodat)

In support of Larry and the problem;

While hoodat is correct in his intepretation of the actual physics, the probelm is still well defined and solvable as it is stated.  This site has had problmes with altered physical constants, and other such things, before this.

Certainly it would be a less intersitng soution.  but WHAT WOULD IT BE (if flow was proportional to ăpressure?)

Posted by Kenny M on 2010-03-17 19:37:50