Bernoulli’s Principle & Bernoulli’s Equation — NEET Physics| Class 11

Real-Life Example

“Mr. Clerk was on the edge of a railway platform, talking to his friend on phone. A train just passed and under the influence of the tremendous speed of the train, Mr. Clark got dragged towards it. Luckily someone from the platform saved him, by pulling him back”

Do you know the reason behind it?

It’s Bernoulli’s principle in real life. Let me explain

Bernoulli’s Principle is a highly challenging but simple physics concept. The equation can help you understand a lot about fluid flow. It illustrates the properties of fluid flow.

Equation 👇

It relates the pressure, velocity, and height of a flowing liquid. When the velocity between two points increases, so does the pressure between them. As a result, we have yet another way of stating Bernoulli’s principle: in a streamlined flow, an increase in fluid velocity must be followed by a decrease in pressure.

Solving Bernoulli’s equation based on the Assumption — Because the fluid is incompressible, the mass flow rates are equal. This gives rise to the so-called continuity equation.

👇

When the fast train passed the station while Mr Clark was standing very close to the railway track on the platform, he was pulled towards the train due to the low-pressure area created by the train’s sheer speed.

The fast-moving train creates a region of low pressure around it (venturi effect), the low pressure can suck in nearby objects and that’s how Mr Clark got dragged towards it

As the train moves forward, it displaces the air in front of it at v. Now, if we consider an area A in front and back of Mr Clerk’s body, the volume flow rate at any given instance remains constant according to the equation of continuity, so: A1*V1 = A2*V2

Where A1 represents the area in front of you and v1 represents the velocity of the air in that area, and the second represents the area behind Mr Clark.

That is, the area is inversely proportional to the velocity through it. Because the air behind Mr Clerk has almost negligible velocity, but the air in front of him has a significant velocity. And, as a result of the moving train, the area for the given volume flow rate has changed; there is now less area in front of Mr Clerk. The pressure for the decreasing force decreases as the area decreases, so the air pressure in front of him is less than that behind.

Related Blog — How to Study Physics for NEET 2022?