Higher: upthrust, floating and sinking

Pressure difference gives upthrust

A submerged object has liquid above its top and bottom surfaces. The bottom is deeper, so pressure there is greater. Pressure forces act perpendicular to surfaces: downward on the top and upward on the bottom. For equal horizontal areas, the larger bottom force gives a resultant upward force called upthrust. Forces on opposite vertical sides cancel in a stationary liquid of uniform density.