Class 9 Science Notes

Class 9 Science Chapter Notes

• 🚀 Chapter 7: Motion
  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, elementary idea of uniform circular motion.
• ⚡ Chapter 8: Force and Laws of Motion
  Force may be defined as a pull or push which changes or tends to changes the state of rest or state of motion of a body.
  
  • If force is applied directly on a body then force is called contact force and if force is applied without actual contact from a distance then it is called action at a distance.
• 🌍 Chapter 9: Gravitation and Flotation
  Gravitation and Flotation, Universal Law of Gravitation, Force of Gravitation of the earth (gravity), Acceleration due to Gravity; Mass and Weight; Free fall. Thrust and Pressure. Archimedes' Principle; Buoyancy.
• ⚙️ Chapter 10: Work, Power And Energy
  Work done by a Force, Energy, power; Kinetic and Potential energy; Law of conservation of energy, commercial unit of Energy.
• 🔊 Chapter 11: Sound
  Nature of sound and its propagation in various media, speed of sound, range of hearing in humans; ultrasound; reflection of sound; echo.