HI GUYS, HERE I EXPLAINED CLASS 9 SCIENCE CHAPTER 10 GRAVITATION IN A INFORMATIVE AND ATTRACTIVE MANNER, READ AND ENJOY IT

1. GRAVITATION
CHAPTER10

2. GRAVITATION :
 Gravitational force is
the force of attraction on a body by
earth.
Ø Example - Leaves and fruits fall from
a tree downwards towards the
ground due to the gravitational pull.

3. CENTRIPETAL FORCE :
 The force that act on a object moving in a circular path and directed towards the centre

4. UNIVERSAL LAW OF GRAVITATION :
 Every object in the universe attracts every other object with a force, which is directly proportional to their
product of mass and inversely proportional to the square of the distance between them.
 Formula :

5. DERIVATION OF UNIVERSAL LAW OF GRAVITATION :

6. IMPORTANCE OF UNIVERSAL LAW OF GRAVITATION :
 The force that binds us to the earth.
 The motion of the moon around the sun
 The motion of planets around the sun
 The tides due to the moon and the sun

7. KEPLER'S LAW :
THREE LAWS DERIVED BY KEPLER ARE :
 KEPLER'S FIRST LAW : { LAW OF ELLIPISE }
All planets travel in
elliptical orbit with the sun as its one foci

8. KEPLER'S LAW :
 KEPLER'S SECOND LAW : { LAW OF EQUAL AREA }
The line joining the sun to a
planets sweeps equal areas in equal interval of time.

9. KEPLER'S LAW :
 Kepler's third law of motion : { law of harmonies }
The square of the time period of revolution of a planet around
the sun in its elliptical orbit is directly proportional to the cube of the semi major axis of the
ellipse

10. FREE FALL :
 When a object falls towards the earth under the gravitational force. Then the body is said to
be in free fall.
ACCELERATION DUE TO GRAVITY :
 Acceleration of a body during free fall towards a celestial body is called acceleration due to
gravity

11. DERIVATION OF :

12. MASS :
 Mass of an object = Measure of its inertia
 Greater mass = Greater inertia
 Mass of an object is constant and does not change from place to place
 The SI unit of Mass is kilogram { KG }
 It is a scalar quantity

13. WEIGHT :
 The force of attraction of the earth on an object is known as the weight of an object
 The SI unit of latest Newton
 It is a vector quantity
 Weight depends on its location
 The formula of weight is w = mg

14. WEIGHT OF AN OBJECT ON THE MOON :
• The weight of an object on the earth is the force with which the earth attracts the object.
M = mass of an object
Wm = weight of the object on moon
Mm = mass of moon
Rm = radius of moon

15. APPLYING UNIVERSAL LAW OF GRAVITATION :

16. THANK YOU
PERSENTED BY -
ELAMARAN