8 Planetary Motion and Gravity Flashcards
What is Kepler’s first law of planetary motion?
The first law of planetary motion states that planets move in elliptical orbits around the Sun, with the Sun at one focus of ellipse (the other is empty). The points in the orbit at which is closest and furthest from the Sun are called the Perihelion and aphelion
What is Kepler’s second law of planetary motion?
Kepler’s second law states that an imaginary line from the Sun to a planet sweeps out equal area in equal intervals in time.
What is Kepler’s third law?
Kepler’s third law states that the square of the orbital period (T) of a planet is proportional to the cube of its mean distance (r) from the Sun
How can you write Kepler’s third law mathematically?
T² α r³ or t²
. . . . . . . . — = a constant
. . . . . . . . r³
What is Newton’s law of Universal Gravitation?
Newton’s law of Gravitation states that every body in the Universe attracts every other body with a force that is directly proportional to the product of their masses and inversely proportional to the square of their distance apart
What is the inverse square law?
The inverse square law states that the intensity of gravitational force is inversely proportional to the square of the distance from the source
What is the Perigee?
The closest point in a satellite’s orbit of the Earth (it is at its fastest here)
What is the Apogee?
The furthest point in a satellite’s orbit of the Earth (it is at its slowest here)
What is the Perihelion?
The closest point in an astronomical bodies’ orbit of the Sun (it is at its quickest here)
What is the Aphelion?
The furthest point in an astronomical bodies’ orbit of the Sun (it is at its slowest here)
What is the inverse equation for force and distance?
F α 1 . . --- . . d² F = force d = distance
