Centre of Pressure
The resultant pressure of a liquid on an immersed body acts through the centre of pressure. This is the point at which the total force due to the liquid is considered to act.

Definition of Centre of Pressure
The centre of pressure is defined as the point at which the total pressure on a surface can be considered to act vertically downward, resulting in the same force and moment as the actual pressure distribution.

Explanation
When a body is immersed in a liquid, it experiences a pressure force due to the weight of the liquid above it. This pressure force is distributed unevenly over the body's surface, with higher pressure at deeper points and lower pressure at shallower points.

The centre of pressure is the point where the total pressure force can be considered to act. It is the point at which the resultant force due to the pressure distribution is applied. The resultant force is the vector sum of all the individual pressure forces acting on the body.

The centre of pressure is not necessarily located at the centre of gravity or the centre of buoyancy. It depends on the shape and orientation of the body, as well as the distribution of pressure forces.

Importance of Centre of Pressure
The concept of the centre of pressure is important in the analysis and design of submerged bodies. It helps in determining the stability and equilibrium of floating or submerged objects.

Knowing the centre of pressure allows engineers to calculate the forces and moments acting on a body due to the liquid pressure. This information is crucial in designing structures that can withstand the pressure forces and maintain stability.

Conclusion
In conclusion, the resultant pressure of a liquid on an immersed body acts through the centre of pressure. This is the point at which the total pressure force can be considered to act vertically downward. Understanding the centre of pressure is essential for analyzing and designing submerged structures, as it helps determine the forces and moments acting on the body.