2. WHY DO OBJECTS FLOAT OR SINK IN A LIQUID ? When an object is put in a liquid. Two forces act on it : 1.Weight of the object acting downwards 2.Buoyant force acting upwards. The upward force acting on an object immersed in a liquid is called buoyant force. Whether the object floats or sinks depends on the magnitude of these two forces.

3. WILL THE OBJECT FLOAT OR SINK ? If the buoyant force exerted by the liquid is less than the weight of the object, the object will sink in the liquid. If the buoyant force exerted by the liquid is equal to the weight of the object, the object will float in the liquid. If the buoyant force exerted by the liquid is more than the weight of the object, the object will rise in the liquid and then float.

4. DENSITY OF FLOATING OBJECTS An object will float in the liquid if its density is less then that of the liquid. (A portion of the object is inside the liquid and the remaining portion is above the surface of the liquid.) An object will also float in a liquid if its density id equal to that of the liquid. (The object is fully immersed in water.) An object will sink in a liquid if its density is more then that of the liquid.

5. FLOATING OBJECTS

6. Sinking Object