Free Fall || Calculate the Value of 'g' || for Class 9 in Hindi

In this Science (Physics) video in Hindi for Class 9 we explained free fall and calculated the value of g, the acceleration due to gravity, on the surface of earth. This is a topic from Chapter 10 - 'Gravitation' for class 9th from NCERT.

Free fall : When a body falls under the influence of gravity only, it is called free fall.

During free fall the acceleration is called the acceleration due to gravity. It is denoted by g and its value, near the surface of earth, is found to be nearly 9.8 ms⁻².

From Newton's second law of motion we can say that the force applied on a body is equal to the product of the mass of the body and the acceleration created on that body, F = ma.

As a body attains an acceleration, g during free fall, we can say that the force due to gravity,
F = mg......... (1)

And from the universal law of gravitation we know,

F = GMm/R² .....(2)
Here, G is the universal gravitational constant, 6.674 x 10^(-11) Nm²kg⁻², M is the mass of the earth, 5.972 x 10^24 kg, and R is the radius of the earth, 6.371 x 10^6 m.

From eqn (1) and (2) we get

g = GM/R²

Putting all these values we get,
g = 9.82 ms⁻²

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🔴 Click here to watch the whole playlist on Chapter 10 : 'Gravitation' for Class 9 :
   • Introduction to Gravitation || in Hin...  

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Previous videos :-

🔴 Introduction to Gravitation
   • Introduction to Gravitation || in Hin...  

🔴 Universal Law of Gravitation
   • Universal Law of Gravitation || for C...