Astronomers
Observed the phases of Venus
Who is Galileo
A line joining a planet and the sun sweeps out......
What is equal ares in equal times
A non-zero total force causes an object to accelerate
What is Newton's first law
ptolemy's model was a geocentric model that attempted to explain what phenomenon
What is retrograde motion
Equal and Opposite Forces
What is Newton's third law
created the first credited heliocentric model of the solar system and explained retrograde motion
Who is Copernicus
How squashed or round an orbit is
What is eccentricity
Gravity is inversely proportional to distance2
What is Newton's law of Gravitation
this is caused by inner planets moving faster than outer planets and overtaking them in their orbit
What is retrograde motion
(m1+m2)p2=a3
What is Newton's generalized version of Kepler's 3rd law
He attempted to explain retrograde motion with his model using epicycles
Who is Ptolemy
Planets move faster when approaching the......
What is the perihelion
For a given force, less massive objects will accelerate more
What is Newton's second law
Main idea of the pythagorean universe was that all motions and objects are
What is circular
If the distance between Earth and sun increases by a factor of 2, how will that affect the orbital period
What is more than twice as long
His naked-eye observations of solar system objects aided Kepler in making his model
Who is Tycho Brahe
The "p" in p2=a3
What is orbital period in Earth years
If the distance between earth and sun increases by 3, how will that affect the gravitational force between the two?
What is decrease by 9
Came up with the first accurate theoretical model explaining planetary motion
Who is Johannes Kepler
What keeps the moon from crashing into Earth due to the force of gravity?
What is angular momentum
He generalized Kepler's third law
Who is Newton
A planet with an eccentricity of exactly one is
What is dead
If the distance between Earth and Sun were to decrease by half, what would happen to the force of gravity?
What is four times stronger
A planet that is passing perihelion is
What is slowing down
As the distance between two solar system objects decreases.....
What is speed increases