Forces and Laws of Motion

Class 9 Science chapter 9, Forces and Laws of Motion, introduces students to the concept of force and its various forms. The chapter covers topics such as contact and non-contact forces, balanced and unbalanced forces, friction, and laws of motion. The chapter also covers the application of these concepts in real-world scenarios, such as the motion of objects under the influence of forces, and the motion of projectiles.

Some of the specific topics that are likely to be covered in this chapter include:

  • Definition and types of force
  • The concept of balanced and unbalanced forces
  • Friction and its effects on motion
  • Newton’s laws of motion and their applications
  • The effect of force on the motion of objects
  • Gravitational force and weight
  • The concept of action and reaction forces

The chapter aims to help students understand the fundamental principles of force and how they can be applied to explain the behavior of objects in the world around them.


A force is a push or pull upon an object resulting from the object’s interaction with another object. Forces can cause an object to accelerate, change direction, or stay in motion. A force is a vector quantity, meaning it has both magnitude and direction. The unit of force in the International System of Units (SI) is the newton (N).

There are several types of forces, including:

  • Contact forces: result from the physical contact between two objects, such as friction, tension, normal force, and air resistance.
  • Non-contact forces: result from the interaction of two objects without physical contact, such as gravity, magnetism, and electric force.
  • Balanced forces: forces that cancel each other out, resulting in no acceleration or change in motion of an object.
  • Unbalanced forces: forces that do not cancel each other out, resulting in acceleration or change in motion of an object.
  • Forces can be represented graphically using force diagrams, which show the direction and relative magnitude of the forces acting on an object

Next Chapter :- Chapter – 10 Gravitation

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