question_answer 27)

Why does an object float or sink when placed on the surface of water?

Answer:

When the object has density less than 1 g cm-1  then it floats on the surface of water, because, it always displaces more weight of water than its own weight. As buoyant force is more than its own weight, therefore, it floats. When the object has density more than 1 g cm-3   then it sinks in water, because it always displaces less weight of water than its own weight. As buoyant force is less than its own weight, therefore, it sinks.