2 replies to this topic

[Dudesons123]

Dear Engineers/Scientists,

I am facing a problem regarding a rectangular tank 5 m long by 2 m wide containing water to a depth of 2 m. How do I determine the total pressure on the end? I got an answer of 9,810Nm^-2 but the answer on the book says 39kNm^-2. I just want to know where I went wrong?

Here is my working:
Area =1/2*AB*BC
=1/2*H*rho*g*H
=1/2*rho*g*H^2

Resultant force per unit width
R=1/2*rho*g*H^2

Total resultant force
R=1/2*rho*g*H^3
=1/2(1000)(9.81)(2)^2
=39240N

P=R/A=39240N/(2m*2m)=9,810Pascals

Thanks.

[Saml]

It seems that the answer is the total force on the end, not the average pressure.

[Francisco Angel]

I agree with Sam.  Are you sure that =39240N isn't the answer you are looking for? "Total pressure" doesn't seem to have a clear meaning, on the other hand  if you integrate pressure you obtain force. Another result that you can calculate is can be "average pressure".

Best regards.