state or law which explains why a ship can easily sink than overturn?
The phenomenon that a ship can sink more easily than it can overturn is primarily due to Archimedes' principle and the concept of stability in naval architecture.
Archimedes' principle states that any object, when partially or wholly immersed in a fluid, experiences an upward buoyant force equal to the weight of the fluid displaced by the object. In the case of a ship, this means that it displaces a volume of water equal to its own weight.
When a ship is floating steadily on the water, the center of gravity (CG) and the center of buoyancy (CB) are in a vertical line, known as the metacenter (M). The metacenter is located above the center of gravity. This configuration is essential for stability.
If a ship were to overturn, the center of gravity would shift to one side, causing a greater portion of the ship's weight to be on one side of the metacenter. This uneven weight distribution creates a restoring moment, causing the ship to return to its upright position.
However, if a ship were to take on water and sink, the center of gravity remains relatively centralized and does not shift as significantly as when overturning. As the ship fills with water, it becomes more massive, increasing its weight. The buoyant force remains the same, but now it acts on a larger weight. This unequal distribution of weight and buoyancy causes the ship to lose stability and eventually sink.
In summary, a ship can sink more easily than overturn due to the stability provided by Archimedes' principle and the distribution of weight and buoyancy. When a ship overturns, the center of gravity shifts, causing a restoring force. When a ship sinks, the center of gravity remains relatively stable, but the increase in weight compared to the buoyant force leads to a loss of stability and eventual sinking.