Topic 8 - Planetary motion and gravity

Question 1

How did Brahe contribute to the transition from a geocentric to a heliocentric model of the Solar System?

Answer 1

He made accurate and precise observations of Mars

Question 2

How did Copernicus contribute to the transition from a geocentric to a heliocentric model of the Solar System?

Answer 2

Copernicus put forward the heliocentric theory in a book

Question 3

What did Kepler discover?

Answer 3

He used Brahe’s measurements to discover that Mars’ orbit was elliptical.
He later published the three laws of planetary motion.

Question 4

What is the 1st Law of Planetary Motion?

Answer 4

Planets move in ellipses with the Sun at one focus

Question 5

What is the 2nd Law of Planetary Motion?

Answer 5

The Sun-planet line sweeps out equal areas in equal times

Question 6

What is the 3rd Law of Planetary Motion?

Answer 6

T^2 / r^3 = constant

Question 7

What does the 3rd Law of Planetary Motion show?

Answer 7

The constant is inversely proportional to the mass of the central body