Solving Fluid Statics Problem: Centre of Pressure

[AppleBite]

Ok, I've come across this problem in fluid statics, but seem to be getting the integration wrong:

"A semicircular plane is submerged vertically in a homogeneous liquid with its diameter d at the free surface. At what depth s is the centre of pressure?"

The answer should be

s = (3*pi*d) / 32

Any ideas?

 

[FredGarvin]

Forget the integration and try the form of the solution found in equation 11-7b in the following link:

http://books.google.com/books?id=Km...X&oi=book_result&resnum=2&ct=result#PPA488,M1