Why does water pressure have a vertical component on sloped container walls?

[alcatras]

Hi. I'm a newb here. I've got a problem about components of force. Water applies force to the walls of container as it does to the bottom. It has only horizontal compenent when the container is straight (walls parallel) but what about in containers with inward and outward sloping walls? In which one vertical component points down? Can anyone explain or give a hint plese?

Thanks

 

[ramollari]

You are not clear what your problem is.
The resultant force depends on what your system boundary is. If you take the whole container wall (bottom and sides) there will be a vertical component pointing downward of the same value, whether they are vertical or sloping.
If you take just the side walls of the container, then there will be a vertical force component pointing downward.

 

[FredGarvin]

The liquid is going to exert a pressure that is normal to the sloped surface. If you coordinate system does not correspond to that slope, you will have to break that force into it's components using basic trig. Everything will be relative to the coordinate system you specify.