Newton’s Law of Universal Gravitation

Presented byVineetha I V

Physical ScienceRoll No : 20

• The idea of gravity was Introduced by Sir Isaac Newton in the late 1600’s

• He was a scientist who combine ideas to explain how the universe operates

How He Discovered it…?

• Newton’s law of Gravitation was discovered while he watched an apple fall from a tree.

• The force that pulled the apple to the ground was the same with which apple attracted earth.

All Matter Is Affected by Gravity

• Because of gravity you are being pulled toward your book, your pencil, and every other object around you.

• You exert an attractive force on everything around you and everything is exerting an attractive force on you.

• This attractive force is called gravity.• All objects experience an attraction toward all other objects

in this universe.

Gravitational Force

Gravitation force depends on two things:

• The mass of the two objects

• The distance between the two objects

Gravitational Force and Mass

• Earth attracts an elephant more than a cat.• Earth attracts coconut more than an apple. • Earth’s gravitational force is greater than that of

moon.

Gravitational force increases as mass

increases.

• Gravitational force is directly proportional to the product of masses.

Gravitational Force and Distance

• Gravity between you and the earth is greater than the gravity between you and the sun.

Gravitational force decreases as distance increases.

• Gravitational force is inversely proportional to the square of distance between the masses

• All objects in the universe attract each other through gravitational force. Every body in the universe attracts every other body with a force which is directly proportional to the product of their masses and inversely proportional to the square of the distance between them.

F M∝ 1M2

d2

F = G M1M2

d2

G = Gravitational Constant & G = 6.67x10-11 Nm2/kg2

This is Law of Universal Gravitation Universal : applies to all objects!!!

• The force acts in the direction of the line connecting the centers of the masses.

Thank You…