Chapter 14.4, Problem 44E

Hydraulics

In Exercises 43–-46, determine the location of the horizontal axis $y_a$ at which a vertical gate in a dam is to be hinged so that there is no moment causing rotation under the indicated loading (see figure). The model for $y_a$ is

$y_a=\bar{y}-\frac{I_{\bar{y}}}{hA}$

where $\bar{y}$ is the y-coordinate of the centroid of the gate, $I_y$ is the moment of inertia of the gate about the line $y=\bar{y}$, h is the depth of the centroid below the surface, and is the area of the gate.