Science in a Minute
Presented by NSF GK-12 and the University of Cincinnati The Earth and the Moon have existed for more than 4.5 billion years. And during
that time, the
Moon has been orbiting the Earth in a choreographed, circular dance. What is not so evident is that the Earth and the Moon are
in a violent game of tug-of-war, each
aggressively pulling on each other. The Moon’s pull is evident in the rise and fall
of tides in Earth’s oceans. But what dictates this
relationship? Sir Isaac Newton mathematically modeled this relationship and
it is called Newton’s Universal
Law of Gravitation. the universal gravitational constant times the mass of each object all divided by the
square of the distance between the two objects.
Fg=G*m1*m2 / r2 G represents the Universal Gravitational Constant
M1 and M2 are the masses of the two
R is the straight line distance between the centers of the two objects. The gravitational force is proportional to the product of their masses. So as the product
so does the gravitational force. Likewise, as the product decreases, so does the
gravitational force. The gravitational force is inversely proportional to the square of the distance.
Thus, as the
distance increases, the gravitational force decreases. And vice-versa. Newton’s Universal Law of Gravitational.