Pressure in Fluids

 8.1 Pressure in Fluids

1. Pascal's principle states that the transmission of pressure exerted on a fluid (liqiod or gas) in an enclosed system is uniform throughout the fluid and in all directions.

2. Operating principle of hydraulic system

• the transmission of pressure on all directions
• the hydralic system is made up of 2 cylindrical pistons of different surface areas
• the fluid is water or oil
• pressure exerted by the small piston is the same as the pressure produced at the large piston

 Pressure at small piston = Pressure at large piston $$\frac{\text{Input force}}{\text{Area of small piston}}$$ $$= \frac{\text{Onput force}}{\text{Area of large piston}}$$

• Application of Pascal's Principle in daily life
• Hydralic jack system
• Hydralic breake system
• Dental chair

3. Bernoulli's principle: when the fluid flows through the narrow part, its velocity increases and the pressure in that region decreases

• application of Bernoulli's principle in daily life
• aerofoil-shaped wings of an aeroplane
• bunsen burner
• helicopter
• drone
• safety lines nearby tracks at railway station