Review Questions

Chapter 22, Part 2 – Planetary Motion

- Explain the contributions of each person:

- Copernicus -
- Tycho Brahe –
- Kepler –
- Newton –
- Ptolemy –
- Galileo –
- Explain Kepler’s first two laws fully. Make a diagram of each and label it.
- What does Kepler’s third law of planetary motion state?
- If the distance to Planet X is 4,000 AU, which is the period? Show all work!
- Galileo proved that our solar system was not geometric. What did he discover and how did he prove it?
- What does Issac Newton’s Universal Law of Gravitation state?
- What happens to the force of gravity between the two objects if their distance increases?
- What happens to the force of gravity between the two objects if their size increases?
- What is the difference between an ellipse and a circle? Which is the shape that the planets follow in their orbits?
- Draw a picture of Ptolemy’s vision of the solar system, and label it.
- What is retrograde motion?
- Why did ancient peoples believe the Earth was the center of the universe?