why does water exert buoyant force on each and every object placed on its surface.
Dear Student,
All fluids exert pressure on the surface of any object in that fluid, but the pressure is not uniform over the surface of the object. Parts of the object that are deeper in the fluid will have more pressure from the fluid pressing against them than parts that are shallower. The amount of the object's surface that is being pressed down by fluid above it will be equal to the amount of surface being pressed up, but the pressure per unit area pressing up will be greater, on average, than the pressure that is pressing down. So this result in greater force upward than force downward on object being submerged in liquid due to pressure of liquid. So the resultant force due to pressure of liquid on object being submerged is upward and this force only is known as buoyant force
Regards
All fluids exert pressure on the surface of any object in that fluid, but the pressure is not uniform over the surface of the object. Parts of the object that are deeper in the fluid will have more pressure from the fluid pressing against them than parts that are shallower. The amount of the object's surface that is being pressed down by fluid above it will be equal to the amount of surface being pressed up, but the pressure per unit area pressing up will be greater, on average, than the pressure that is pressing down. So this result in greater force upward than force downward on object being submerged in liquid due to pressure of liquid. So the resultant force due to pressure of liquid on object being submerged is upward and this force only is known as buoyant force
Regards