buoyant force
What explains buoyant force? Recall from the earlier lesson "Pressure of Fluids" that a fluid exerts pressure in all directions but the pressure is greater at greater depth. Therefore, the fluid below an object exerts greater force on the object than the fluid above the object. This is illustrated in Figure below . Buoyant force explains why objects may float in water. No doubt youve noticed, however, that some objects do not float in water. If buoyant force applies to all objects in fluids, why do some objects sink instead of float? The answer has to do with their weight.