CLASS 9 PHYSICS

CLASS 9 PHYSICS

Physics is the study of energy and matter in space and time. It deals with how the fundamental constituents of the universe interact. Content for Class 9 Physics covers the concepts of Motion, Force and Laws of Motion, Gravitation, Work and Energy and Sound.

CHAPTER-1 MOTION

Motion is a change in the position of an object over time. Motion is described in terms of displacement, distance, velocity, acceleration, time and speed.

CONTENTS

1.1 Describing Motion

1.2 Equations of Motion by Graphical Method

1.3 Graphical Representation of Motion

1.4 Measuring the Rate of Motion

1.5 Rate of Change of Velocity

1.6 Uniform Circular Motion

CHAPTER- 2 FORCE AND LAW OF MOTION

Newton’s second law of force and laws of motion states that “the rate of change of momentum is directly proportional to the forces acting on the object.” I.e: the object moves in the direction in which the force acts. It clearly explains that the force is a product of the mass, accelerated to a certain distance (kg).

CONTENTS

2.1 Conservation of Momentum.

2.2 Force.

2.3 Newton’s First Law of Motion.

2.4 Newton’s Second Law of Motion.

2.5 Newton’s Third Law of Motion.

CHAPTER- 3 GRAVITATION

Gravitation or just gravity is the force of attraction between any two bodies. All the objects in the universe attract each other with a certain amount of force, but in most of cases, the force is too weak to be observed due to the very large distance of separation.

CONTENTS

3.1 Archimedes’ Principle.

3.2 Gravitation.

3.3 Mass and Weight

3.4 Thrust and Pressure

CHAPTER- 4 WORK AND ENERGY

Work = Force x Displacement Unit of workdone = Joule = Newton x metre 1 Joule work is said to be done when 1 Newton force is applied on an object and it shows the displacement by 1 meter. The capacity of a body to do work is called the energy of the body.

CONTENTS

4.1 Kinetic and Potential Energy

4.2 Law of Conservation of Energy

4.3 Work and Power

CHAPTER- 5 SOUND

Sound is a mechanical energy which produces sensation of hearing. Sound is produced due to the vibration of different objects. The sound wave propagates as compressions & rarefactions in the medium. Sound waves are longitudinal waves.

CONTENTS

5.1 Characteristics of Sound Waves.

5.2 Production and Propagation of Sound.

5.3 Range of Hearing and Ultrasound.

5.4 Reflection of Sound.

5.5 The Human Ear.