Class 9 Science Chapter 6: How Forces Affect Motion
NCERT Exploration | Class 9 Science | 2026–27
Explore force, balanced and unbalanced forces, friction and Newton’s three laws of motion with easy-to-understand study notes, important diagrams, examples, activities, practice questions and worksheets.
This chapter builds on Chapter 4, where students learned to describe motion using position, velocity and acceleration, and now explores what causes changes in motion.
Table of Contents
📅 Last Updated: August 2026
📘 Syllabus: Based on the latest CBSE Class 9 (2026–27) syllabus
✅ Updated Resources Include:
- Chapter-wise Study Notes
- Free PDF Downloads
- MCQs
Chapter Overview
| Information | Details |
|---|---|
| Class | 9 |
| Subject | Science |
| Textbook | Exploration |
| Chapter | 6 |
| Chapter Title | How Forces Affect Motion |
| Academic Session | 2026–27 |
| Resources | Notes, Worksheets, Questions, Tests & Revision |
About This Chapter
In this chapter, students explore:
- The concept of force
- Balanced and unbalanced forces
- Net force
- Friction
- Newton’s First Law of Motion
- Newton’s Second Law of Motion
- Newton’s Third Law of Motion
- Forces acting on a system of objects
- Internal and external forces
- Tension
- Applications of Newton’s laws in everyday situations
Important Concepts
Force: A force can affect the motion of an object.
Friction: Friction acts opposite to the direction of motion.
Newton’s First Law: An object remains at rest or continues with constant velocity unless a net force acts on it.
Newton’s Second Law: A net force produces acceleration; acceleration increases with net force and decreases with mass.
Newton’s Third Law: When one object exerts a force on another, the second object simultaneously exerts an equal and opposite force on the first.
Key Formula
F = ma
where:
- F = net force
- m = mass
- a = acceleration
Important Diagrams
- Forces acting on an object
- Balanced and unbalanced forces
- Friction force
- Newton’s First Law illustrations
- Position-time/velocity-time graphs
- Newton’s Second Law experiment
- Newton’s Third Law force pairs
- Rocket launching
- Earth and fruit gravitational forces
- Two boxes connected by a string
- Internal and external forces acting on a system
Practice Questions
The chapter itself ends with 16 “Revise, Reflect, Refine” questions, covering conceptual questions, net force, Newton’s laws, graphs, numerical problems, friction, collisions and applications.
🎯 Learning Outcomes
After completing Class 9 Science Chapter 6 – How Forces Affect Motion, students will be able to:
- Explain the concept of force and describe how force can affect the motion of an object.
- Distinguish between balanced and unbalanced forces and determine the net force acting on an object.
- Explain the role of friction in everyday motion.
- Understand and apply Newton’s First Law of Motion and the concept of inertia.
- Explain the relationship between force, mass and acceleration using Newton’s Second Law.
- Use the relation F = ma to solve numerical problems.
- Understand Newton’s Third Law of Motion and identify action–reaction force pairs.
- Explain everyday applications of Newton’s laws, such as walking, rowing, jumping and rocket propulsion.
- Distinguish between internal and external forces when considering a system of objects.
- Apply Newton’s laws to simple situations involving connected objects and tension.
- Interpret simple motion graphs in situations involving forces.
- Use observations and experiments to investigate the effects of force, friction, mass and acceleration.
🔑 Key Topics
- Concept of Force
- Balanced and Unbalanced Forces
- Net Force
- Force of Friction
- Newton’s First Law of Motion
- Inertia
- Newton’s Second Law of Motion
- Force, Mass and Acceleration
- Newton’s Third Law of Motion
- Action and Reaction Forces
- Forces Acting on a System of Objects
- Internal and External Forces
- Tension in Connected Objects
- Applications of Newton’s Laws in Everyday Life
- Force, Motion and Acceleration
- Graphs Related to Motion and Force
- Numerical Problems Based on Force and Acceleration
⭐ Class 9 Science Chapter 6 Study Resources
📌 Important Questions
Most important questions to prepare for exams and chapter revision.
🎯 Competency-Based Questions
Application-focused questions designed to develop deeper understanding.
🧮 Numerical Problems
Practice problems based on force, mass, acceleration, friction and Newton’s laws.
🎁 Free Class 9 Worksheets
Try our free printable Class 9 worksheets before exploring the complete practice packs.
Class 9 Science – Chapter 6: Free Sample Worksheet Questions + Answer Key
NCERT Exercise Solutions
Practise the questions from Chapter 6 and check your answers with our step-by-step solutions.
Chapter 6 – NCERT Exercise Solutions
Why Students Choose Our Class 9 Science Resources?
2026–27 Focused
Printable PDFs
Original Practice
Chapter-Wise Resources
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Answer Keys
❓FAQ
Q1. What textbook is used for Class 9 Science in 2026–27?
Answer about the new NCERT Exploration textbook.
Q2. Which chapter is this page about?
Chapter 6 of Exploration is How Forces Affect Motion
Q3. Are these NCERT textbook copies?
No. Our worksheets, notes and practice materials are independently created learning resources. They are designed to support students studying the NCERT curriculum.
Q4. Are the worksheets free?
Explain which resources are free and which may be available as complete practice resources.
Q5. Are answer keys included?
Explain depending on the particular resource.
Q6. Are these resources suitable for school revision?
Yes.
Q7. Will more Chapter 6 resources be added?
Yes. New resources may be added as they are developed.
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