Question

Torque on the walls of a container due to a fluid.

Answer 1

Pressure is indeed F/A however force varies upon the depth of the water therefore to find the force you need to"divide each area into small bands of areas, each having its own pressure (rho)gh, then add up those little forces you have got to gain the total force on the wall"Therefore you will get (integrate)(rho)gh x wdh from 0 to h

So from this you would get 0.5rho g w h^2