Applications of Pressure in Liquids

A) Public Water Supply System.

Public water supply system

1) In a public water supply system, water from a river or a dam is pumped to a water treatment plant.

2) Due to gravitational pull, water in the storage tank is maintained at a high pressure and this enables water to flow to the houses of the consumers which are lower.

B) The Walls of a Dam

The side view of a dam

1) The walls of a dam increase in thickness downwards.

2) A thicker wall is required to withstand greater pressure since water pressure increases with depth.

C) Fire Hose Used by a Fire-fighter 

Fire-fighter using a fire hose

1) 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.

2) To produce a pressurised water jet, the water is accelerated by an electric pump before flowing through the fire hose.

D) Sphygmomanometer for Measuring Blood Pressure

A doctor taking a patient's blood pressure

1) A doctor using a special mercury-filled manometer called a sphygmomanometer to measure the blood pressure of a patient.

2) On releasing the air in the cuff slowly, the doctor taken the maximum blood pressure (systolic) reading at the instant he/she hears the first sound of a spurt of blood.