Buoyant force on a floating body

When a body is partially submerged in a liquid, with the remainder in contact with air (as shown in figure), the buoyant force of the body can also be computed using equation (L-10.3). Since the specific weight of the air (11.8 ) is negligible as compared with the specific weight of the liquid (for example specific weight of water is 9800 ),we can neglect the weight of displaced air. Hence, equation (L-10.3) becomes

        (Displaced volume of the submerged liquid)

             = The weight of the liquid displaced by the body.

The buoyant force acts at the centre of the buoyancy which coincides with the centeroid of the volume of liquid displaced.