Kepler's third law of planetary motion states that: A) orbital ...

[segrsyd]

Kepler's third law of planetary motion states that:
 
  A) orbital period is double the semi-major axis.
  B) the planets move at constant speeds at all points in their orbits.
  C) all the planets move around Earth in elliptical orbits.
  D) orbital period and semi-major axis are related.

Question 2

Which of the following is a reason why the Ptolemaic model was the accepted model of the Universe?
 
  A) It was a very good predictor of planet positions.
  B) The authority of Aristotle was immense.
  C) It proved that the Sun was at the center of the Universe.
  D) The multiple revisions to the model made it completely accurate.

[hanadaa]

Answer to Question 1

D

Answer to Question 2

B