What is the lift force in case 2?

[yilbaris]

We all know the lift force in case 1, what about case 2 ?

 

[Orodruin]

Note that there is also a force from the liquid pushing down on the additional wings you put in ...

 

[pbuk]

Buoyant force depends only on the amount of water displaced, not the shape of the object displacing it.

 

[SteamKing]

We all know the lift force in case 1, what about case 2 ?View attachment 89160

If by "lift force", you actually mean "buoyancy", this can be calculated for case 2, although it is slightly more complicated than case 1.

Remember Archimedes' Principle:

https://en.wikipedia.org/wiki/Archimedes'_principle

Note: in technical use, "lift force" is usually reserved for a force which is created by a dynamic situation, like the lift generated by an airplane's wings when flying.
OTOH, "buoyancy" usually refers to a force created by a static situation, like the displacement of fluid by a floating object.

 

[yilbaris]

Thank you for answers,

? To calculate the resultant force is possible, but i wonder distribution of force. ?

 

[pbuk]

Every point on the submerged surface of the object feels a normal force proportional to the pressure at that depth $\rho g h$

 

[Orodruin]

Every point on the submerged surface of the object feels a normal force equal to the pressure at that depth $\rho g h$

A force can never equal a pressure, the dimensions are different. An area element is subjected to a normal force equal to the pressure multiplied by the area

 

[yilbaris]

Thank you all.

------------------SOLVED------------

 

[pbuk]

A force can never equal a pressure, the dimensions are different. An area element is subjected to a normal force equal to the pressure multiplied by the area

I wanted to steer clear of elemental areas for the sake of clarity but I take your point; I have amended 'equal' to 'proportional'.