Which of the following statements is correct about the location of centre of pressure? 

Concept

For a plane surface of arbitrary shape immersed in a liquid in such a way that the plane of the surface makes an angle θ with the free surface of the liquid:

A = Total area of inclined surface

h̅ = Depth of centre of gravity of inclined area from free surface

h* = Distance of centre of pressure from free surface of liquid

\({h^*} = \frac{{{I_G}{{\sin }^2}\theta }}{{A̅ h}} + ̅ h\)

For vertical plane surface: θ = 90°

\({h^*} = \frac{{{I_G}}}{{A̅ h}} + ̅ h\)

So we can conclude that

• Centre of pressure lies below the centre of gravity of the vertical plane surface
• The distance of the centre of pressure from free surface of liquid is independent of the density of the liquid

The total pressure force P exerted by the static fluid on a vertically immersed surface is given by:,

P = PGA

PG = Pressure at the center of gravity of the vertical plate

⇒ P = ρ g h̅ A

⇒ P = w A x

Where , h̅  = x