# Class 9 Physics

 PHYSICS | Motion, Force and Work Marks |  27 out of 80

## MOTION

Distance and displacement, velocity; uniform and non-uniform motion along a straight line; acceleration, distance-time and velocity-time graphs for uniform motion and uniformly accelerated motion, equations of motion by graphical method; elementary idea of uniform circular motion.

## Force and Newton’s laws

Force and Motion, Newton’s Laws of Motion, Action and reaction forces, Inertia of a body, Inertia and mass, Momentum, Force and Acceleration. Elementary idea of conservation of Momentum.

## Gravitation

Gravitation; universal law of gravitation, force of gravitation of the earth (gravity), acceleration due to gravity; mass and weight; free fall.

## Floatation

Thrust and pressure. Archimedes’ principle, buoyancy, elementary idea of relative density.

## Work, energy and power

Work done by a force, energy, power; kinetic and potential energy; law of conservation of energy.

## Sound

Nature of sound and its propagation in various media, speed of sound, range of hearing in humans; ultrasound; reflection of sound; echo and SONAR. Structure of the human ear (auditory aspect only).

## Numerical 