Pressure in liquids
Fluid pressure is a measurement of the force per unit area. Fluid pressure can be caused by gravity, acceleration, or forces in a closed container. Since a fluid has no definite shape, its pressure applies in all directions. Fluid pressure can also be amplified through hydraulic mechanisms and changes with the velocity of the fluid. In a fluid column, as the depth increases, the pressure increases as well. Pressure increases because as you go deeper, fluid at a lower depth has to support fluid above it as well. Therefore to define it, we can say that fluid pressure is the pressure at a point within a fluid arising due to the weight of the fluid.
Pressure in liquids is equally divided in all directions, therefore if a force is applied to one point of the liquid, it will be transmitted to all other points within the liquid.
The pressure in fluids can be calculated using the following relation.
Pressure at a point in a fluid= Pressure at the reference point+(The density of the fluid acceleration due to gravity (considering earth g = 9.8 m/s)*height from the reference point) or in short: Pfluid = P + ρgh
The SI Unit (International System of Unit) of Pressure is Pascal.
Water exerts an upward force on the object and that upward force is known as buoyancy. So any object immersed in the fluids experiences buoyancy.
For example, if you throw a balloon in the water it will float whereas if you throw any heavy object like a brick, it will sink. This is because gravitational force is applied on the brick which pulls it downward. And on balloon upward force by water is applied which pushes it up. And that is why balloon floats, and brick sinks.
The pressure in the public water system supply is provided mechanically by a pumping system.