Explanation:

Introduction:
In order to understand why a ship floats while an iron nail sinks, we need to consider the concept of buoyancy and the relationship between weight and volume of an object.

Buoyancy:
Buoyancy is the upward force exerted by a fluid on an object immersed in it. It is responsible for making objects float or sink in a fluid. When an object is placed in a fluid, such as water, it displaces some of the fluid and experiences an upward force equal to the weight of the fluid it displaces.

Weight and Volume:
The weight of an object is the force exerted on it due to gravity. It depends on the mass of the object and the acceleration due to gravity. The volume of an object is the amount of space it occupies. In the case of a ship and an iron nail, the ship has a much larger volume compared to the iron nail.

Archimedes' Principle:
Archimedes' principle states that an object immersed in a fluid experiences an upward buoyant force equal to the weight of the fluid it displaces. This principle helps us understand why the ship floats while the iron nail sinks.

Explanation:
- The ship is heavier than an iron nail because it has a greater mass.
- However, when the ship is floating on the water, it displaces a large volume of water, which results in a buoyant force acting on the ship.
- According to Archimedes' principle, the buoyant force is equal to the weight of the water displaced by the ship.
- As the ship displaces a large volume of water, the weight of the water it displaces is equivalent to the weight of the ship itself.
- This means that the buoyant force acting on the ship is equal to the weight of the ship, balancing the downward force due to gravity.
- As a result, the ship floats on the water surface.

Comparison to the Iron Nail:
- An iron nail, on the other hand, has a much smaller volume compared to the ship.
- When the nail is placed in water, it displaces a very small volume of water.
- The weight of the water displaced by the nail is much smaller than the weight of the nail itself.
- Therefore, the buoyant force acting on the nail is not enough to balance the downward force due to gravity, causing the nail to sink.

Conclusion:
The ship floats because the weight of the water it displaces is equal to the weight of the ship itself. The iron nail sinks because the weight of the water it displaces is much smaller than its own weight. The principle of buoyancy, as described by Archimedes, explains this phenomenon.