Viva Physics for Class IX

Contents:

Chapter 1: Motion • State of rest and motion • Describing the position of an object • Scalar and vector quantities • Distance and displacement • Uniform and nonuniform motion • Speed • Velocity • Acceleration • Graphical representation of motion • Distance-time graphs • Calculation of speed from a distance-time graph • Displacement-time graphs • Speed-time graphs for a body moving along a straight line in a direction: Velocity-time graphs • Calculation of distance travelled from speed-time graphs • Velocity-time graphs • Derivation of the equations of motion by graphical method • Uniform circular motion

Chapter 2: Force and Laws of Motion • Force • Galileo's concept of motion • Newton's laws of motion • Inertia and mass • Newton's first law of motion • Newton's second law of motion • Momentum • Change in momentum and the second law of motion • Direction of force and direction of motion • Units of force • Impulse of a force • Newton's third law of motion • Illustrating Newton's third law of motion • Conservation of momentum

Chapter 3: Gravitation • Newton's universal law of gravitation • Centre of mass and centre of gravity • Gravitational force between objects of different sizes • Newton's third law of motion and gravitation • Application of Newton's law of gravitation • Falling objects and acceleration due to gravity, motion of particles under gravity • Gravity and gravitation • Equations of motion for a body moving under gravity • Mass and weight

Chapter 4: Archimedes• Principle and Floatation • Thrust and pressure • Buoyancy or upthrust • Archimedes• principle • Application of Archimedes• principle • Floatation • Hydrometer

Chapter 5: Work, Energy and Power • Work • Work done when force is not along the direction of motion • Energy • Kinetic energy • Potential energy • Are various forms of energy inter-convertible: Transformation of energy • The simple pendulum: An example of the conservation of mechanical energy • Conservation of energy • Rate of doing work: Power

Chapter 6: Sound • Productions of sound • Sound needs a medium to propagate • Propagation of sound • Waves and wave motion • Mechanical and non-mechanical waves • Longitudinal and transverse waves • Longitudinal Waves • Compression and rarefaction • Transverse waves • Crest and trough • Characteristics of waves • Relationship between wave velocity, frequency, and wavelength for a periodic wave • Speed of sound • Sound travels slower than light • lighting and thunder • Characteristics of sound • Reflection of sound waves • Echo • Reverberation • Practical applications (or uses) of multiple reflection of sound • Megaphone • Ear trumpet (or hearing aid) • Sound boards and curved ceiling and walls in large halls • Audible range • Ultrasound • The human ear

Model Questions for the Year-End Examination

Value-Based Questions

About the Authors:

Dr. S K Jain did his postgraduation from IIT Delhi and PhD from University of Delhi. He specializes in Physical Chemistry and takes special interest in Electrochemistry and Energy Conversion. He has published over fifty research papers in journals of international repute. Dr. Jain has visited several countries on research assignments as Research Associate and also as visiting Scientist. He has written many textbooks for school and college students.

Dr. Shailesh K Jain did his postgraduation from IIT Kanpur and PhD from the United Kingdom. He specializes in the field of Heterogeneous Catalysis and has special interest in the field of Analytical Chemistry related to the metallurgical operations. He has published several research papers and co-authored many textbooks for school and college students. He is involved actively in the popularization of Science at School/undergraduate levels.