Gravitation Class 9th Notes - Free NCERT Class 9 Science Chapter 10 Notes - Download PDF

Gravitation Class 9 Notes Science Chapter 10- Download Free PDF

In Chapter 10 of Class 9 Science, we look into the interesting world of gravity. Gravitation, one of nature's fundamental forces, governs the attraction between masses. Gravity shapes our universe and daily experiences in a variety of ways, from the motion of celestial bodies to the simple act of dropping a pen.

We have provided comprehensive Gravitation class 9 notes to help you understand this important chapter. These class 9 physics chapter 10 notes are a concise yet thorough resource that covers the essential concepts and key points outlined in the NCERT Textbook. Whether you're studying for an exam or just need a quick review, these Gravitation notes class 9 will help you understand the fundamentals of gravity.

These CBSE class 9 physics ch 10 notes aim to simplify complicated concepts by using clear explanations, diagrams, and examples to make them accessible and understandable to Class 9 students. This chapter will teach you about the principles of gravitational attraction, its effects on planetary motion, and its applications in a variety of real-world scenarios.

Download the PDF ch 10 physics class 9 notes to improve your understanding and grasp of this fascinating subject. With these notes, you'll be well-prepared to answer questions, solve problems, and expand your understanding of Gravitation. Discover the wonders of gravity and solve its mysteries with our comprehensive Class 9 Science notes on Gravitation.

Also, students can refer,

• NCERT notes Class 9 Science
• NCERT Solutions for Class 9 Science Chapter 10 Gravitation
• NCERT Exemplar Class 9 Science Solutions chapter 10 Gravitation

NCERT Class 9 Physics Chapter 10 Notes

What is the Centripetal Force?

• We know that an object in circular motion keeps on changing its direction.

• The velocity of an object also changes.

• A force named Centripetal Force acts upon an object which keeps it moving in a circular path.

• The centripetal force is exerted from the centre of the circular path followed.

Example: Rotation of the Moon around Earth is possible because of the centripetal force exerted by Earth.

Newton's Observations

• Apple falls on the ground because the earth attracts it towards itself.

• Can Apple also attract the earth? - Yes. apple also attracts the earth as per Newton's third law. But the mass of the earth is extremely larger than Apple's mass hence, the force applied by Apple is negligible and Earth never moves towards it.

• Newton then suggested that every object in this universe attracts another object. This force of attraction is called Gravitational Force.

Universal Law of Gravitation by Newton

• The Universal Law of Gravitation states that every object attracts another object with a specific force.

• This force is directly proportional to the product of the masses of both the objects

( F∝m₁m₂)

• Also, this force is inversely proportional to the square of the distances between the two objects.

F∝1/r²

• Observe the given figure below. The force of attraction between two objects is shown. The masses of the two objects are m1 and m2 respectively. These two objects are ‘d’ distance apart.

F∝m₁

F∝m₂

F∝1/r²

From the previous equations, we can write :

F∝m₁m₂/r²

Remove the proportionality we get proportionality constant G as follows:

F=Gm₁m₂/r²

This is the mathematical representation of Newton’s Universal Law of gravitation

SI Unit of G: Nm² kg^-2

G = 6.673 × 10^-11 Nm² kg^-2

• The proportionality constant G = Universal Gravitational Constant.

Important phenomena of the universe –

• Earth’s gravitational force

• The circular trajectory of the moon around the sun

• Planets revolve around the sun

• Tides due to the moon

• Acceleration due to gravity

When an object falls towards the Earth there is an acceleration related to the movement of the object. This acceleration is the acceleration due to gravity.

• Symbole: g

• SI Unit of g: m s^-2

• F=mg

• g=GM/r²

• The value of ‘g' varies in different parts of the earth.

• The value of ‘g' depends upon the distance of the object from the earth's centre.

• The value of ‘g' is greater at the poles and lesser at the equator. But we take the same value of g all over.

What is Free Fall?

When an object falls towards the earth because of the earth’s gravity and there is no other force acting upon it, the object is in a free-fall state. Air resistance is negligible.

The value of ‘g' is the same on the earth, thus the equations of motion for an object with uniform motion are valid.

v=u+gt

s=ut+gt²/2

2gs=v²-u²

Mass v/s Weight

Significance of NCERT class 9 physics chapter 10 notes

Comprehensive Revision: The NCERT Gravitation class 9 notes provide a comprehensive overview of the chapter, allowing students to thoroughly review all key concepts.

Detailed Understanding: These class 9 physics chapter 10 notes provide detailed explanations of the chapter's main concepts, ensuring that students understand the principles of gravitation.

Simplicity: The Gravitation notes class 9 are intended to be straightforward and easy to understand, making complex concepts more accessible to students.

Step-by-Step Approach: Each concept is explained step by step, allowing students to follow along and grasp the material more effectively.

CBSE Syllabus Coverage: Because Gravitation is part of the CBSE Science syllabus for class 9, these notes are perfectly aligned with the curriculum, ensuring that students cover all of the required topics.

Offline Preparation: CBSE class 9 physics ch 10 notes are available in PDF format, allowing students to download and access them offline, allowing for convenient preparation at any time and from any location.

NCERT solutions of class 9 subject-wise

• NCERT solutions for class 9 Maths
• NCERT solutions for class 9 Science

NCERT Class 9 Exemplar Solutions for Other Subjects:

• NCERT Exemplar Class 9 Maths solutions
• NCERT Exemplar Class 9 Science solutions

Class 10 Chapter Wise Notes