# Applications of Bernoulli’s principle

1. Statements based on Bernoulli’s principle are …

(1) lifting force on an aircraft

(2) hydraulic pump

(3) mosquito sprayers

(4) hot air balloon

Solution

Statements based on Bernoulli’s principle are

(1) lifting force on airplanes and

(3) mosquito sprayers

(2) Hydraulic pump under Pascal’s principle

(4) Air balloon based on Archimedes’ principle

2. Statements relating to the application of Bernoulli’s principle are …

(1) venturi meter

(2) mosquito sprayers

(3) barometer

(4) thermometer

Solution

Statements based on Bernoulli’s principle are

(1) venturi meter and

(2) mosquito spray

(3) a barometer based on hydrostatic pressure

(4) mercury thermometer or alcohol based on expansion

3. The tools based on Bernoulli’s principle are …

(1) hydraulic pump

(2) carburetor

(3) venturi meter

(4) thermometer

Solution

(2) carburetor and

(3) venturi meter

(1) hydraulic pump based on hydrostatic pressure, Pascal’s law

(4) mercury or alcohol thermometer based on expansion

4. Aircraft wings are designed to have maximum lift force, such as a picture. If v is the velocity of the air flow and P is the air pressure, then according to the Bernoulli principle, the design is made so that …

Solution

In order for the plane’s wings to lift upward, the air thrust at the bottom of the wing is larger than the thrust force on the top of the wing.

The thrust force on the underside of the wing is greater if the air pressure at the bottom of the wing is greater. P = F / A, where the pressure of P is directly proportional to F. If the pressure is greater then the force also increases.

Bernoulli’s principle states that the air pressure at the bottom of the wings is great when the air velocity at the bottom of the wing is small.

v_{A}> v_{B} so that P_{A} <P_{B}