Fluid Statics

Example 3:

A vertical gate of 2m x 2m rests with its top edge 1 m below the water level. Find the depth of such a horizontal line that a) the force on the top half is equal to the pressure on the bottom half. b) The moments of the force at both half about the line are equal.

Solution :

Given data: - Area of the gate = 2x2 = 4 m 2
Depth of the top edge 1 m
(a)    Let, the depth of such a line is x from the top of the gate.


Equating these two x =1.24m.
(b)    Now if be the depth of centre of pressure from the top of water surface.

Fig. Ex 3

Taking moments about (A...A)

                                  and solve for x

Answer: -     1.24m and 1.167m.

Prev
First | Next | End