CBSE Class 9 Science Chapter 9 - Force and Laws of Motion Revision Notes - Free PDF Download
Force and Laws of Motion is one of the most important chapters covered in the Class 9 Physics syllabus. Class 9 Science Chapter 9 notes, prepared by the highly experienced teachers at Vedantu, provide explanations to all the essential concepts of this chapter. These notes are available in the PDF format on Vedantu and students can download them for free of cost. Force and laws of motion are among the fundamental concepts of Physics, so this chapter is important from the examination point of view. Students can revise these concepts by referring to the Class 9 Science Chapter 9 notes.
Vedantu also provides free NCERT Solutions to all the students. You can download Class 9 Maths NCERT Solutions to help you to revise complete syllabus and score more marks in your examinations.
Force is a physical quantity that has a magnitude as well as a direction. The ‘direction of force’ indicates the direction in which the force is applied. A force is a pull or a push on a body. Application of a force changes the state of motion or of rest of an object. Force can change the velocity and direction of an object. Also, force is capable of changing the shape of an object.
Force and Laws of Motion Class 9 Notes CBSE Science Chapter 9 [Free PDF Download]
FAQs on Force and Laws of Motion Class 9 Notes CBSE Science Chapter 9 [Free PDF Download]
1. Why do bicycles slow down when we stop pedalling?
A bicycle slows down when we stop pedalling because of the frictional force that acts in the opposite direction to the motion. Force and Laws of Motion class 9 notes have this real-life example explained in it along with other illustrations. Read the chapter and the study material to develop a clear understanding of various forces.
2. Which law of motion gives the measure of force?
Newton’s second law of motion can be used to find out the measure of force.
3. What is electrostatic force?
An electrostatic force exists between particles due to their charges. Electrostatic forces can be attractive or repulsive in nature.
4. Does the speed of a body change when it moves on a flat surface?
No, its speed does not change and remains the same.
5. How are revision notes beneficial for Chapter 9 of Class 9 Science?
The revision notes are designed by professionals keeping in mind the calibre of each student of a particular class. Therefore, students can benefit greatly from using these notes to learn Chapter 9 because all the information is compressed into crisp notes that students can easily remember and use as a last-minute guide for the exam. The important topics and questions are highlighted, giving students an additional advantage in guiding them in their journey to score good and amazing results.
6. What are the concepts covered in Chapter 9 of Class 9 Science?
Chapter 9 of Class 9 Science is 'Laws of Motion,' and as the title says, terms related to motion like inertia, rest, acceleration, etc., are what students learn from this Chapter. The concepts covered in Chapter 9 of Class 9 Science are:
Force and the various laws of motion
Types of forces: Balanced and unbalanced
Conservation of Momentum
7. Why do you fall forwards and backward when a moving bus brakes and accelerates from rest, respectively, according to Chapter 9 of Class 9 Science?
This answer can be explained by the concept of inertia that students learn in Chapter 9 of Class 9 Science. When a bus moves and the brakes are suddenly applied, the lower part of the body comes to rest. Due to the inertia of motion, the upper part continues to be in the same state. Thus we fall forward. But, when a bus accelerates from rest, the lower part gets in motion first while the upper part stays in rest, and hence we fall backward.
8. Why do leaves get detached from a branch when a tree is shaken vigorously?
In Chapter 9 'Laws of Motion' of Class 9 Science, students are taught about a concept known as inertia which is a tendency to remain in an existent state. A tree's branch is always at rest. When a branch is shaken vigorously, it is the branch that attains motion, not the leaves. Due to the inertia of the rest of the leaves, they tend to remain in their original position as a result of which the leaves detach and fall down.
9. Is Chapter 9 of Class 9 Science difficult to understand?
The Chapter 'Laws of Motion' ranges in the difficulty level of easy to moderate, meaning that the Chapter is not difficult to study. Students have a lot of concepts related to motion, inertia, mass, and the various laws, but all of these are usually easy to understand and remember. The revision notes of Chapter 9 of Class 9 Science are available free of cost on the Vedantu website and the Vedantu app.