Question

A circular plate 5.0 m diameter is immersed in such a way that its greatest and least depth below the free surface are 3 m and 1 m respectively. determine the position of the centre of pressure.

(a) 2.5 m

(b) 5 m

(c) 4.5 m

(d) 6 m

This question was posed to me by my school principal while I was bunking the class.

Origin of the question is Horizontal and Inclined Plane Surface Submerged in a Liquid topic in chapter Hydrostatic Forces on Surfaces of Fluid Mechanics

Answer 1

Right choice is (a) 2.5 m

For explanation I would say: centre of pressure, ŷ=I*sin²θ/Aĥ + ĥ

                                                                                        …….ĥ=(y+dsinθ)

                                                       =3.142*2.5^4*sin²23.58/3.142*2.5^2*(1+2.5sin23.58)+*(1+2.5sin23.58)

=2.5 m.