Applications of Pressure In Liquids

1. Public Water Supply System

• The reservoir is placed at an elevated location so that the water will have sufficient pressure to flow to consumers located at lower grounds.
• A water tank is usually built atop the roof of each house to store water and maintain constant water pressure.
• A high-rise building is supplied with water from its own water tank which is situated at the highest level. 

2. The Walls of a Dam

• A dam is built across a river to collect water for the purpose of water supply, irrigation and generation of hydroelectric power.
• The walls of a dam increase in thickness downwards.
• This is because a thicker wall is required to withstand greater pressure since water pressure increases with depth.

3. Fire Hose Used by a Fire-fighter

• A fire-fighter requires a fire hose for directing a water jet of very high pressure to put out fire in a high-rise building.
• To produce a pressurised water jet, the water is accelerated by an electric pump before flowing through the fire-hose.

4. IV Injection under Gravity

• IV injection is used for injecting solutions of salt or medicine into the vein of a patient.
• IV bottle should be suspended at the optimum height, h to ensure that the fluid (solutions) gauge pressure of the IV bottle is greater than the pressure in the vein.