Transcript newton*s law of universal gravitation and it*s application

States
that all objects
in the universe attracts
each other by the force
of gravity.
 The
size of the force depends on the
two(2) factors:
A. The masses of the objects
B. The distance between them
The force of gravity increases as
the mass of object increases,
Gravitational forces decreases as
the distance between the objects
increases.
 Mass
is a measure of how much material is
in an object, but weight is a measure of
the gravitational force exerted on that
material in a gravitational field; thus, mass
and weight are proportional to each other,
with the acceleration due to gravity as the
proportionality constant. It follows that
mass is constant for an object (actually this
is not quite true, but we will save that
surprise for our later discussion of
the Relativity Theory), but weight depends
on the location of the object.
a.) The weight of an object varies
according to the force of gravity
pulling on you and the force of
gravity varies according to distance
from center of the Earth.
b.) Your mass does not, your mass is
same anywhere on the Earth, on
the Moon, and even on Jupiter. It is
your weight that changes. Because
of the great distance of an object
to the Earth, it has less weight but
it does not affect the mass.
c.) According to Newton’s second(2nd)
law:
Force = mass*acceleration (can be
rewritten in terms of weight)
weight = mass * acceleration due to
gravity
Into an equation:
N = Mass * 9.8 m/s/s or w = m * g
Since the unit of weight is Newton(N)
and unit of mass is kilograms, on the
surface of the earth, the acceleration
due to gravity is 9.8 m/s/s(9.8 m/s2).
 What
Really Happened with the Apple?
 Now
came Newton's truly brilliant insight:
if the force of gravity reaches to the top of
the highest tree, might it not reach even
further; in particular, might it not reach all
the way to the orbit of the Moon! Then,
the orbit of the Moon about the Earth could
be a consequence of the gravitational
force, because the acceleration due to
gravity could change the velocity of the
Moon in just such a way that it followed an
orbit around the earth.
 Kepler's
First Law: on Orbits
Every planet moves in an elliptical orbit, with
the Sun at one focus.

Kepler's Second Law: on Areas
As a planet moves in its orbit a line drawn from the Sun to the Planet sweeps out
equal areas in equal time intervals.
The line joining the two bodies (the sun and the revolving object) sweeps
equal areas in equal times.
The graphic precisely displays Kepler's second law. The area of every
triangle formed is exactly the same area. Also notice as the planet or
satellite moves closer to the sun, the speed of its orbit increases, but
when it is located farther away from the sun, the speed in which the
planet or satellite revolves around the sun is slower.

Kepler's Third Law: on Periods
It stated that if P is the period and M is the length of semimajor axis of a
planet's orbit, then the ratio P²/M³ is the same for all the planets.
Table of values that verifies Kepler's third law.
The linearity of the line between the period and lenth of the semimajor
axis verifies that relationship.