Gravity | Orbitals | Kepler's Law Flashcards
magnitude of the gravitational force on either particle
Fg
Every particle of matter in the universe attracts every other particle with a
force that is _______
to the “product of the masses of the particles”
Directly proportional
Every particle of matter in the universe attracts every other particle with a
force that is _______to the square of the distance between them.
Inversely proportional
The force is extremely small for bodies that are small enough to be brought into the
laboratory, but it can be measured with an instrument called
Torsion balance
Henry Cavendish used in 1798 to determine
Gravitational constant (G)
Is the most important force on the scale of planets, stars, and galaxies. It is
responsible for holding our earth together and for keeping the planets in orbit about the sun.
Gravitation
important on the cosmic scale because at a distance,
without any direct
Gravitational force
is the energy stored of an object because of its distance
above the surface of the Earth.
Gravitational Potential Energy
GPE formula
Eg = mgΔh
is the object’s change in gravitational potential energy in Joules
ΔEg
is the vertical displacement of the object in meters
Δh
the simplest case. It is also an important case, since many artificial
satellites have nearly circular orbits and the orbits of the planets around the sun are also fairly circular
Circular orbit
The only force acting on a satellite in circular orbit around the earth is
Earths Gravitational attraction
The first law explains
that all planets move in
elliptical orbits with the
sun at one focus.
Law of orbits
The second law describes a
line that connects a planet to
the sun and sweeps out
equal areas in equal times.
When a planet is near the
sun, it travels faster and
sweeps through a longer path
in a given time.
Law of areas
The third law mathematically expressed as the square of the period of any planet is
proportional to the cube of the semi-major axis of its orbit.
LAW OF PERIODS
