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CHAPTER 12: GRAVITATION AND NEWTON'S SYNTHESIS - Coggle Diagram
CHAPTER 12: GRAVITATION AND NEWTON'S SYNTHESIS
Newton's Law of Universal Gravitation
where
states that every point mass in the universe attracts every other point mass with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between them.
Vector Form of Newton's Law of Universal Gravitation
In Vector Form:
The gravitational forces acting between the two particles form action-reaction pair. Where r^12 is a unit vector pointing from m2 to m1.
Gravity Near the Earth's Surface; Geophysical Application
Acceleration due to gravity varies on the Earth's surface because of the altitude, shape of the Earth and the local geology.
For example:
Gravitational constant cn be related to local acceleration of gravity.
From the formula:
Satellites and "Weightlesness"
Satellites
an object in space that orbits or circles around a bigger object.
natural (such as the moon orbiting the Earth)
artificial (such as the International Space Station orbiting the Earth).
The tangential speed must be high enough so that the satellites does not return to Earth but not so high that it escapes Earth's gravity altogether.
Weightlesness
Objects in orbit are said to experience weightlessness.
still have gravitational force on them.
the satellite is in
free fall
, there is no normal force.
also known as
Apparent Weightlesness
(can be experienced on Earth but brief)
Examples: Man paragliding, astronauts on the Moon, free falling elevator.
Kepler's Laws and Newton's Sythesis
Kepler's Law (Laws of Planetary Motions)
1st Law: The law of ellipses
Each planet moves in an elliptical way with its star(Sun) at one focus.
2nd Law: Law of equal Areas
an imaginary line drawn from each planet to the Sun sweeps out equal areas n equal times.
3rd Law: Law of Periods
The square of planet's orbital time is proportional to its average distance from the star (Sun) cubed.
Newton's synthesis
Gravitational Field
is the gravitationalForce per unit mass:
Gravitational Field due to a single mass,
M
:
Types of Forces in Nature
Gravity
an invisible force that pulls objects toward each other.
Electromagnetism
occurs between electrically charged particles.
Weak Nuclear Forces
responsible for some types of radioactive decay
Strong Nuclear Forces
binds proton and neutrons together in the nucleus of an atom.
Principle of Equivalence; Curvature of Space; Black Holes
fundamental law of physics that states that gravitational and inertial forces are of a similar nature and often indistinguishable.
