Astronomy Answer Sheet
Lab 4: Kepler's Laws (answer sheet)
1. a: semi-major axis
b: semi-minor axis
c: focus
d: center
2. The distance from the center to a focus is 31 millimeters and the length of the semi-major axis is also in millimeters. The numbers are not even and cannot be simplified any further than what they are since 31 is a prime number. The number is 31/102, or 31 divided by 102 which results in 0.303921568627451.
3. Kepler’s first Law is that all planets orbit in an elliptical (egg shaped) orbit where the sun is one focal point.
4.
Focus: A
Aphelion: C
Perihelion: B
Increasing Speed: B to D
Decreasing Speed: D to C
Planet has greatest speed B
Planet has lowest speed C
5.
a) e = 0
b) e = 0.25
c) e = 0.40
6. Kepler’s second law is that a line that connects a planet to the sun will cause the planet to travel the same distance in the same time.
7. Kepler's Third Law relates the years (P) it takes to go around the Sun in an
orbit of a given astronomical units (a).
The simplified relationship (formula) is: P/a .
8. P would be the same. Even though the second orbit is not a circle, due to Kepler’s second law, it will travel the same amount of distance in the same time. So since the value of a is the same, it doesn’t matter what shape it is in, it will still take the same amount of time.
9. According to your book, what is the Newtonian form of Kepler's Third Law? (See pages 38 and 39 of your textbook.) Newtonian’s form of Kepler’s law extends Kepler’s law by adding the three laws of motion and the law of gravity which in turn extended the application of mapping orbits to more than planets. It extended it to comets, spacecraft, stars, and moons to name a few.
Write the full formula here: 4 times pie(squared) over (or divided by) GM
Skip questions 10 - 12, but the (Optional) section is actually mandatory:
(You should click on and use this sheet in the lab since it
1. a: semi-major axis
b: semi-minor axis
c: focus
d: center
2. The distance from the center to a focus is 31 millimeters and the length of the semi-major axis is also in millimeters. The numbers are not even and cannot be simplified any further than what they are since 31 is a prime number. The number is 31/102, or 31 divided by 102 which results in 0.303921568627451.
3. Kepler’s first Law is that all planets orbit in an elliptical (egg shaped) orbit where the sun is one focal point.
4.
Focus: A
Aphelion: C
Perihelion: B
Increasing Speed: B to D
Decreasing Speed: D to C
Planet has greatest speed B
Planet has lowest speed C
5.
a) e = 0
b) e = 0.25
c) e = 0.40
6. Kepler’s second law is that a line that connects a planet to the sun will cause the planet to travel the same distance in the same time.
7. Kepler's Third Law relates the years (P) it takes to go around the Sun in an
orbit of a given astronomical units (a).
The simplified relationship (formula) is: P/a .
8. P would be the same. Even though the second orbit is not a circle, due to Kepler’s second law, it will travel the same amount of distance in the same time. So since the value of a is the same, it doesn’t matter what shape it is in, it will still take the same amount of time.
9. According to your book, what is the Newtonian form of Kepler's Third Law? (See pages 38 and 39 of your textbook.) Newtonian’s form of Kepler’s law extends Kepler’s law by adding the three laws of motion and the law of gravity which in turn extended the application of mapping orbits to more than planets. It extended it to comets, spacecraft, stars, and moons to name a few.
Write the full formula here: 4 times pie(squared) over (or divided by) GM
Skip questions 10 - 12, but the (Optional) section is actually mandatory:
(You should click on and use this sheet in the lab since it