Let's say I initially have an open, empty, soda can. I then turn it over and lower it into a bowl of water, and then release it. Obviously water rises to some level in the cup and then there is air at the top of the can, which was initially the bottom.
Are there only three forces on the can once it reaches equilibrium?
Buoyant force from the water (up)
Weight of the can itself (down)
Air pressure inside the can acting on the water surface (down)
Let me know if all of these are right, otherwise my equation for total forces is...
F_b = mg + P where m is the mass of the can, and P is the air pressure in the cup