Brown Astronomy Unit 2 Webassign Questions
As Saturn lies at about 10 AU from the Sun, out there the Sun's gravity would be
100 times weaker
Compared to orbital velocity, escape velocity is about
41% greater
On what did Copernicus and Ptolemy agree?
All orbits are circular
Upon which point did Kepler and Copernicus disagree?
All planetary orbits must be circular
The Copernican heliocentric model was actually first proposed by
Aristarchus
Which of these concepts was NOT part of Ptolemy's model?
Planets moved in ellipses
Which concept below was NOT part of Kepler's Laws?
Retrograde motion requires epicycles when the planet lies at opposition, closest to us.
Retrograde motion
Describes the portion of a planet's path in the sky when it stops moving eastward and for a while turns westward
The Ptolemaic model of the universe
Explained and predicted the motions of the planets with deferents and epicycles
What was one of Newton's contributions to astronomy?
He developed a theory of gravity that could explain orbital motion
What contribution to astronomy was made by Tycho Brahe?
He made extensive and detailed observations of the positions of the planets
What was one of the contributions made by Copernicus to astronomy?
He said that the Earth is not the center of the universe
Which of the following is one of the many contributions made by Galileo to astronomy?
He used a telescope to observe sunspots and the rotation of the Sun
The force of gravity between two objects
Increases with the mass of the objects and decreases with the distance between them
Scientists today do not believe the Ptolemaic model because
It has been proven to be incorrect
The Ptolemaic picture of the universe probably survived for so long because
It is consistent with the doctrines of the Church
What was the greatest contribution of the Greeks to modern thought?
Their concept of the universe as something to be studied, questioned, and explained
Long ago, people probably observed the heavens because
They relied on their knowledge of the heavens to know when to plant crops and how to navigate ships