PHYSICS

CH: 09
GRAVITATION

,It is said that, once the great scientist , Isaac Newton was sitting in
the garden under an apple tree. Accidently an apple fell from the tree
on him. He thought about it and concluded that the apple had fallen
because of the force of attraction exerted by the earth on it. He called
this force, the gravitational force. Similarly, a ball dropped from
some height falls down because of the force of attraction of the earth.
In fact, the earth attracts all the bodies towards its Centre. This force
of attraction is called gravitational force of attraction.

,• The gravitational force also acts between the sun and the earth
• The gravitational force is responsible for the motion of the earth around the sun.
• Gravitational force between the sun and another planets is responsible for the motion of the
planets around the sun.
• Gravitational force between the earth and the moon responsible for the motion of the moon
around the earth.
• Newton concluded that every object in this universe attracts every other object with a force .
• The gravitational force is the force of attraction with which every object in this universe is
attracted towards every other object places anywhere in the universe, irrespective of their
shape or size.

, NEWTON’S LAW OF GRAVITATION OR UNIVERSAL
LAW OF GRAVITATION

According to Newton’s law of gravitation,
“every object in this universe attracts every other object with a force,
which is directly proportional to the product of their masses and
inversely proportional to the square of the distance between their
centers.”