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