Newton’s law of Universal
Gravitation
www.batesville.k12.in.us/physics/PhyNet/.../Gravity/gravitation_notes.pp...
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.
Newton’s Law of Universal
Gravitation
http://scienceblogs.com/startswithabang/upload/2009/07/meet_our_second_moon/400px-NewtonsLawOfUniversalGravitation.svg.png
Why does the moon not fall straight
down onto the earth?
Henry
Cavendish’s
experiment
determined the
proportionality
constant
G
in 1798.
http://www.newscientist.com/data/images/archive/1639/16390101.jpg
Law of Universal Gravitation
Gravitational Force (N)
M1 and M2 = 10 kg
8E-11
7E-11
6E-11
5E-11
4E-11
3E-11
2E-11
1E-11
0
0
20
40
60
Distance (m)
80
100
 Write in your own words What Newton’s law of Universal
Gravitation force is and label all parts of the formula.
 Newton's law of gravitation
 The principle that expresses the force of
gravitational attraction between two bodies
as a function of their mass and their distance.
 Expressed mathematically, F = G m1m2/r
2where F is the force in Newtons, m 1 and m 2
are the masses of the bodies in kilograms, G is
the gravitational constant, and r is the
distance between the center of the bodies in
meters.
 Newton's Principle of Gravitation is an
example of an inverse square law.