(i) Name the forces acting on a body when it is fully or partially immersed in a liquid.
(ii) Briefly explain, why some objects float and some sink in the liquid?
(i) When an object is immersed in a liquid, two forces act on it
(a) Weight of the object which acts in downward direction, i.e. it tends to pull down the object.
(b) Buoyant force (upthrust) which acts in upward direction, i.e. it tends to push up the object.
(ii) Three conditions of floating and sinking are
(a) If the buoyant force exerted by the liquid is less than the weight of an object, the object will sink in the liquid.
(b) If the buoyant force is equal to the weight of the object, then the object will float in the liquid.
© If the buoyant force is more than the weight of the object, the object will rise in the liquid and then float.