Question

In a dam,where water has a height of $h$ then centre of pressure is

• A. below the height of $\frac{h}{2}$
• B. above the height of $\frac{h}{2}$
• C. at the height of $\frac{h}{2}$
• D. any of the above

Answer 1

The correct option is A below the height of $\frac{h}{2}$

Variation of pressure with depth, $P=\rho gh$

where $h$ is the depth of point under the surface of water.

As pressure of water increase linearly with depth, so average of pressure below height $h/2$ is greater than average of pressure above height $h/2$. This makes the center of pressure to shift below height $h/2$.