Term
click below
click below
Term
Normal Size Small Size show me how
GRAVITATION
SCERT CLASS IX PHYSICS PART 1 CHAPTER 4
Term | Definition |
---|---|
FORCE OF GRAVITY | the force of attraction in which the earth attracts all objects towards its centre. |
UNIVERSAL LAW OF GRAVITATION | The force of mutual attraction between two bodies is directly proportional to the product of their masses and inversely proportional to the square of the distance between then. |
KEPLER'S FIRST LAW | Planets revolve in elliptical orbits around the sun. |
KEPLER'S SECOND LAW | The line joining the planet and the sun sweep areas in equal intervals of time. |
KEPLER'S THIRD LAW | The cube of the mean distance of a planet from the sun is directly proportional to the square of its orbital period. |
TWO TYPES OF FORCES IN NATURE | Contact & Non-Contact Forces |
EXAMPLES OF CONTACT FORCES | Viscous force, Surface tension, Elastic force and force of friction |
EXAMPLES OF NON CONTACT FORCES | Nuclear force, Electromagnetic force, Gravitational force |
WHICH IS THE STRONGEST FORCE? | Nuclear force |
WHICH IS THE WEAKEST FORCE? | Gravitational force |
FORCE OF ATTRACTION AT THE CENTRE OF EARTH | Zero |
ACCELERATION DUE TO GRAVITY | Objects are accelerated towards the earth due to the force of attraction of earth. |
WEIGHT OF THE BODY | The force with which the earth attracts the body towards its centre. |
UNIT OF WEIGHT | Newton |
WHAT IS 1 kgwt? | Equal to the force of attraction exerted by the earth on an object of mass 1kg. |
HOW MASS IS MEASURED? | Common Balance |
HOW WEIGHT IS MEASURED? | Spring Balance |