## Bernoulli's Principle

 2.6 Bernoulli's Principle

 Bernoulli's principle In a steady flow of a fluid, fluid pressure decreases as fluid velocity increases and vice versa.

Application of Bernoulli's principle

1. Insecticide sprayers
• The piston is pushed in, high air velocity on nozzle
• The air pressure in the nozzle is lower than atmospheric pressure
• Atmospheric pressure acts on the surface of the insecticide
• Insecticide moves up through the tube

2. Bunsen burner
• Gas flowing at high velocity, resulting in a lower pressure inside than atmospheric pressure
• Air from outside is drawn in, mixed with gas
• Gas and air mixture enables the burning of gas

3. Plane wing (aerofoil)
• Air moves at higher velocity over the wing, resulting in lower pressure
• Air moves slower under the wings, resulting in a higher pressure
• Pressure below wing is higher than the pressure at the top
• Resultant force acting upwards (lift)

4. Car spoiler ( inverted aerofoil)
• Air moves at lower velocity over the wing, resulting in higher pressure
• Air moves faster under the wings, resulting in a lower pressure
• Pressure below wing is lower than the pressure at the top
• Resultant force acting downwards

## Bernoulli's Principle

 2.6 Bernoulli's Principle

 Bernoulli's principle In a steady flow of a fluid, fluid pressure decreases as fluid velocity increases and vice versa.

Application of Bernoulli's principle

1. Insecticide sprayers
• The piston is pushed in, high air velocity on nozzle
• The air pressure in the nozzle is lower than atmospheric pressure
• Atmospheric pressure acts on the surface of the insecticide
• Insecticide moves up through the tube

2. Bunsen burner
• Gas flowing at high velocity, resulting in a lower pressure inside than atmospheric pressure
• Air from outside is drawn in, mixed with gas
• Gas and air mixture enables the burning of gas

3. Plane wing (aerofoil)
• Air moves at higher velocity over the wing, resulting in lower pressure
• Air moves slower under the wings, resulting in a higher pressure
• Pressure below wing is higher than the pressure at the top
• Resultant force acting upwards (lift)

4. Car spoiler ( inverted aerofoil)
• Air moves at lower velocity over the wing, resulting in higher pressure
• Air moves faster under the wings, resulting in a lower pressure
• Pressure below wing is lower than the pressure at the top
• Resultant force acting downwards