9. Force and Laws of Motion-The First Law of Motion Science Class 9 In English-CBSE Notes
Explore science cbse notes for Class 9 Chapter 9. Force and Laws of Motion Topic The First Law of Motion in English medium for exams preparation.
9. Force and Laws of Motion-The First Law of Motion Science Class 9 In English-CBSE Notes
Popular Topics Covered
Our study material includes
- cbse notes for class 9 science chapter 9. Force and Laws of Motion topic The First Law of Motion in english
- class 9 science chapter 9. Force and Laws of Motion cbse notes
- cbse class 9 science chapter 9. Force and Laws of Motion notes in english
- class 9 science chapter 9. Force and Laws of Motion study notes
- class 9 science chapter 9. Force and Laws of Motion revision notes
- cbse notes for class 9 science chapter 9. Force and Laws of Motion
- class 9 science chapter 9. Force and Laws of Motion summary notes
- cbse class 9 science chapter 9. Force and Laws of Motion quick notes
All Topics Chapter 9. Force and Laws of Motion
- 1. Force and its Kinds
- 2. The First Law of Motion
- 3. The Second Law of Motion
- 4. The Third law of motion
- 5. Assignment
- 6. page 6
- 7. page 7
Notes
9. Force and Laws of Motion-The First Law of Motion Science Class 9 In English-CBSE Notes
9. Force and Laws of Motion
The First Law of Motion
Chapter 9. Force and Laws of Motion
(1) The First Law of Motion:
The first law of motion states;
"An object remains in a state of rest or of uniform motion in a straight line unless
compelled to change that state by an applied force."
In other words: all objects resist a change in their state of motion.
- The first law of motion tells us that the motion of an object due to applying unbalanced force. When an unbalanced force is applied to any object it moves due to force.
- The first law of motion indicates that when an unbalanced external force acts on an object, its velocity changes, that is, the object
gets an acceleration.
Inertia:
Defintion: There is a resistance offered by an object to change its state of motion. If it is at rest it tends to remain at rest; if it is moving it tends to keep moving. This property of an object is called its inertia.
- Inertia is a property or tendency of every object.
- Inertia is measured by mass of an object.
- The heavier object has the greater inertia than the light object.
Law of inertia:
The tendency of undisturbed objects to stay at rest or to keep moving with the same velocity is called inertia.
Types of inertia :
(i) Inertia of Rest
(ii) Inertia of motion
(iii) Inertia of direction
Examples of inertia:
(I) Travelling in a car: While travelling in a motorcar can be explained on the basis of the law of inertia. We tend to remain at rest with respect to the seat until the drives applies a braking force to stop the motorcar. With the application of brakes, the car slows down but our body tends to continue in the same state of motion because of its inertia. A sudden application of brakes may thus cause injury to us by impact or collision with the panels in front. Safety belts are worn to prevent such accidents. Safety belts exert a force on our body to make the forward motion slower.
(ii) Standing in bus: When we are standing in a bus and the bus begins to move suddenly. Now we tend to fall backwards. This is because the sudden start of the bus brings motion to the bus as well as to our feet in contact with the floor of the bus. But the rest of our body opposes this motion because of its inertia.
(iii) Sharp turning at high speed of a car: When a motorcar makes a sharp turn at a high speed, we tend to get thrown to one side. This can again be explained on the basis of the law of inertia. We tend to continue in our straight-line motion. When an unbalanced force is applied by the engine to change the direction of motion of the motorcar, we slip to one side of the seat due to the inertia of our body.
- A body will remain at rest unless acted upon by an unbalanced force.
(iv) Hitting aarom coins by a stricker: When we attempt a sharp horizontal hit at the botton of the pile using another carom coins or stricker. If the hits is strong enough. the bottom coin moves out quickly and removed and due to inertia of the other coins makes them fall vertically on the table.
This is why, the first law of motion is also known as the law of inertia.
Mass: The quantity of material present in a object is called its mass.
The mass of an object is a measure of its inertia.
Differences between Inertia and Mass:
| Inertia | Mass |
| 1. Inertia is a property of an object. 2. Intertia of a object is measured by its mass. | 1. Mass is a amount of material of an object. 2. Mass is a measurable quantity itself. |
All Topics Chapter 9. Force and Laws of Motion
9. Force and Laws of Motion-The First Law of Motion Science Class 9 In English-CBSE Notes
Hindi Medium Students/Teachers/Tutors:
All Chapters science Class 9
CBSE Notes for Class 9 science Chapter 9. Force and Laws of Motion – The First Law of Motion
The CBSE Notes for Class 9 science Chapter 9. Force and Laws of Motion – The First Law of Motion are prepared to help students understand every concept in a simple, clear, and well-organized manner. These notes are based on the latest CBSE syllabus and are suitable for regular classroom learning, homework, revision, and examination preparation. Every topic is explained using easy language so that students can learn important concepts without difficulty and develop a strong academic foundation.
Studying directly from the textbook is essential, but during revision students often need concise study material that highlights only the most important information. These chapter-wise notes provide exactly that. Instead of reading lengthy chapters repeatedly, students can quickly revise definitions, concepts, facts, examples, and important points in a short period of time. This approach saves valuable study time while improving understanding and retention.
Why Study Chapter 9. Force and Laws of Motion – The First Law of Motion Using Our Notes?
Every chapter contains several important concepts that require careful understanding. Our notes present these concepts in a logical sequence so students can connect ideas easily. Difficult topics are simplified with easy explanations, making learning enjoyable for students of different learning abilities. Whether you are preparing for classroom discussions, assignments, periodic tests, or annual examinations, these notes provide a reliable source for effective revision.
- Prepared according to the latest CBSE curriculum.
- Simple and student-friendly explanations.
- Chapter-wise organized content for easy learning.
- Important concepts, definitions, and key points included.
- Useful for quick revision before examinations.
- Supports self-study and classroom learning.
- Helps improve conceptual understanding and confidence.
- Suitable for homework, assignments, and test preparation.
Benefits of Reading CBSE Notes Regularly
Consistent revision is one of the most effective ways to achieve academic success. Reading CBSE Notes for Class 9 science Chapter 9. Force and Laws of Motion – The First Law of Motion regularly helps students remember important information for a longer period. Since the content is arranged systematically, students can identify important topics quickly and revise them whenever required.
These notes also help students improve answer-writing skills by presenting information in a structured format. Instead of memorizing lengthy paragraphs, students learn how to organize answers using important points and concepts. This not only improves writing quality but also increases confidence during examinations.
How to Use These Notes Effectively
To get the best results, students should first read the NCERT textbook carefully and understand the chapter. After completing the textbook, they should study these notes to reinforce important concepts. During revision, students can focus on highlighted definitions, important facts, and key ideas before solving textbook exercises and practice questions. This learning strategy improves both understanding and long-term memory.
Teachers and parents can also use these notes as a quick reference while helping students revise lessons or complete assignments. Since the content is concise and well-organized, it becomes easier to explain difficult topics within a limited amount of time.
Features of Our CBSE Notes
Every chapter on our platform is created with the objective of making learning easier for students. Our educational team regularly reviews and updates the content according to the latest CBSE guidelines so that students always receive reliable and accurate study material.
- Easy-to-understand chapter explanations.
- Important definitions and key concepts.
- Well-structured content for faster revision.
- Based on the latest CBSE syllabus.
- Helpful for school exams and annual examinations.
- Free online access on desktop and mobile devices.
Prepare Better with Chapter-wise CBSE Notes
Success in examinations depends on consistent practice and smart revision. These CBSE Notes for Class 9 science Chapter 9. Force and Laws of Motion – The First Law of Motion are designed to reduce study pressure by presenting important information in a concise and meaningful way. Students can use them throughout the academic session for daily learning as well as last-minute revision before examinations.
Along with these notes, students are encouraged to solve NCERT textbook questions, practice important questions, and attempt sample papers regularly. Combining concept-based learning with regular practice helps improve problem-solving ability, analytical thinking, and overall academic performance. With disciplined study habits and quality learning resources, students can build confidence, strengthen their understanding of every chapter, and achieve excellent results in school examinations.
9. Force and Laws of Motion-The First Law of Motion Science Class 9 In English-CBSE Notes Study Materials For Class 6 to 12
If you want to improve your academic performance, start studying with free CBSE notes for all classes. These notes are designed to make learning simple, clear, and effective for every student. Choose your class, explore the chapters, and begin your preparation with the latest cbse notes today.
