I was currently reading about Archimedes' principle and saw following picture on the wikipedia page:
It says that the medium is water. I know from Archimedes' principle that we can calculate the buoyancy force by calculating the hydrostatic pressure on the top of the object and below the object, and subtract the forces resulting in the buoyancy force.
However, why does this work? As far as I know, the hydrostatic pressure depends on depth ($p=ρ*g*h$) because there are water layers on top of each other which increase the pressure with depth. However,under the cube (where it says 2943 Pa) there is no water above it, but we can still calculate the water hydrostatic pressure like we're used to. Why?