Physics exercise: Pressure in this Fresh Water Tank

[Vale Tum]

Homework Statement

The manhole cover of the fresh water tank is screwed on and the tank is filled to the indicated level. Determine the pressure at the bolts.

Relevant Equations

dF=P*dA ; H=550mm ; Varignon's Theorem

I did some of the exercise, but I don't know how to apply the momentum :'(

 

[erobz]

Can you explain this some more. The lid is put on the tank (making a seal). The tank is initially filled with air, then water is pumped in, trapping a pocket of air between the water surface and the lid. Is that the scenario?

Or looking at your solution attempt a bit more, it looks like a fluid statics problem where you find the force acting at the center of pressure on the plate. Either way, I think you need clearer diagramming of where/how this plate is oriented on the tank.

 

[haruspex]

Not sure I understand the diagrams. Pls supply the full description of the problem and state your coordinate system.

 

[Herman Trivilino]

Can you explain this some more. The lid is put on the tank (making a seal). The tank is initially filled with air, then water is pumped in, trapping a pocket of air between the water surface and the lid. Is that the scenario?

I think that's what's happening. The air is compressed, so the solution is to find the change in pressure given the corresponding change in volume.