NEWTON'S UNIVERSAL LAW OF GRAVITATION

1. WELCOME

2. Newton’s Law of
Universal Gravitation
Physical Science
ARUN KUMAR C

3. Isaac Newton
 1666, England (45 years
after Kepler).

4. Newton’s Law of Universal
Gravitation
 Any two objects attract each other with a
gravitational force, proportional to the
product of their masses and inversely
proportional to the square of the distance
between them.
 The force acts in the direction of the line
connecting the centers of the masses.

5. Newton’s Law of Universal
Gravitation
http://scienceblogs.com/startswithabang/upload/2009/07/meet_our_second_moon/400px-NewtonsLawOfUniversalGravitation.svg.png

6. Why does the moon not fall straight
down onto the earth?
ANS: GRAVITATIONAL FORCE

7. Henry
Cavendish’
s
experiment
determined the
proportionality
constant
G
in 1798.
http://www.newscientist.com/data/images/archive/1639/16390101.jpg

8. The Value of G.
G= 6.67 x 10-11 N m2 / kg2

9. Questions
 If the planets are orbiting the sun , what force is
keeping them in orbit?
 What force keeps the moon in its orbit?
 Could the force of gravity be universal?

10. Problem 1
 Two spheres of mass 35kg are 60m apart.
A) What force does one exert on the other?
B) If the mass of on is tripled and the radius
is quadrupled how does the force change?

11. Problem 2
 Two spheres of equal mass have a force of
gravity of 7x10-9 exerted on each other. If
the distance between them is 7m, find the
mass.

12. Problem 3
 Find the value of the gravitational
acceleration g. The mass of the earth is 6.0
x 1024kg.

13. THANK YOU