Question

A cork floats while the nail sinks in water. Which of the following statements is the reason for the same.
(A) Weight of cork is $<$ than buoyant force while the weight of the nail is $>$ than buoyant force
(B) Weight of cork is $>$ than buoyant force while the weight of the nail is $>$ than buoyant force
(C) Weight of cork is $<$ than buoyant force while the weight of the nail is $<$ than buoyant force
(D) Weight of cork is $>$ than buoyant force while the weight of the nail is $<$ than buoyant force

Answer 1

We will first understand the terms involved in this question which are buoyant force and weight. The buoyant force known as buoyancy is a type of force that causes any objects to float in water or any fluid. It is the force exerted on an object by the medium in which the object is partly or wholly immersed in a fluid.

Complete Step by step solution:
If we observe that when a body is placed in water, it starts to displace some amount of water which is equal to the weight of that object. The amount of water displaced by the weight of an object can be calculated by the density of the object and which relates to its volume. The volume of a wooden rod and an iron rod can be the same but their weights and their densities can be different.
If we compare the objects given in this question which is a cork and an iron nail. If we compare their weights we can conclude that the weight of cork is very less than the iron nails. As the weight of wooden cork is less than the buoyant force acting on the cork due to water is less while in the case of the iron nail the weight of the nail is much greater than the buoyant force of the water. As a result, it does not float on water while the wooden cork can float on water.
Hence option (A) is the correct answer.

Note:
The iron block sinks in water but the iron ship having the same weight as the iron block does not sink. This occurs due to the result of buoyant force resulting in them. Therefore, due to their weight, they displace the water and the amount of water that is being displaced in the upward direction can be explained in terms of buoyant force.