Why Can't I Solve This Kepler's Law Problem Correctly?

  • Context: Graduate 
  • Thread starter Thread starter takoma
  • Start date Start date
  • Tags Tags
    Law
Click For Summary
SUMMARY

This discussion centers on the application of Kepler's Laws to solve a specific problem involving the comparison of various orbital characteristics of planets. The user struggles with determining the correct relationships between period, area, speed, and time based on Kepler's Laws. The correct answers are identified as follows: A) Less than (L), B) Equal to (E), C) Greater than (G), D) Less than (L), and E) Greater than (G), leading to the final answer of "LEGGL". The user is encouraged to validate these conclusions against Kepler's Laws.

PREREQUISITES
  • Understanding of Kepler's Laws of Planetary Motion
  • Familiarity with orbital mechanics and the relationship between distance and period
  • Knowledge of area swept out by planets in orbit
  • Basic mathematical skills for interpreting ratios and comparisons
NEXT STEPS
  • Study Kepler's Third Law of Planetary Motion in detail
  • Learn about the concept of equal areas being swept out in equal times
  • Explore the implications of distance on orbital speed
  • Review examples of orbital mechanics problems for practical application
USEFUL FOR

Astronomy students, physics enthusiasts, and educators seeking to deepen their understanding of planetary motion and Kepler's Laws.

takoma
Messages
4
Reaction score
0
For some reason, I just can't seem to get this problem right even though I go through it tons of times and I earnestly believe that my answer is correct, but I guess not.

http://img.photobucket.com/albums/v45/takomastock/640ddd43.jpg"

"Use Kepler's Laws to determine the comparison between various items shown in the figure. Assume the figure is drawn to scale.
(Select G-Greater than, L-Less than, E-Equal to, If the first is G and the rest E, enter GEEEE)."

A) A planet with half the average distance to the star would have ... half the period.
B) If area 1 and 3 are equal the time to go from D to E is ... the time to go from A to B
C) The speed at A ... the speed at D
D) The planets's average speed between D and E is ... the average speed between A and B
E) Time to go from B to C is ... time from A to B

I've come up with all these answers and all are wrong. I even narrowed it down to believe that the last 4 answers are "EGLE", but it seems it's wrong.

These are all the possibilities I've come up with, and nope. Still incorrect.

EEGEG

LEGEG

EEGLG

EEGLE

LEGLE

GEGLE

GEGLG

--

Please freaking enlighten me. :cry:
 
Last edited by a moderator:
Astronomy news on Phys.org
takoma said:
For some reason, I just can't seem to get this problem right even though I go through it tons of times and I earnestly believe that my answer is correct, but I guess not.

http://img.photobucket.com/albums/v45/takomastock/640ddd43.jpg"

"Use Kepler's Laws to determine the comparison between various items shown in the figure. Assume the figure is drawn to scale.
(Select G-Greater than, L-Less than, E-Equal to, If the first is G and the rest E, enter GEEEE)."

A) A planet with half the average distance to the star would have ... half the period.
B) If area 1 and 3 are equal the time to go from D to E is ... the time to go from A to B
C) The speed at A ... the speed at D
D) The planets's average speed between D and E is ... the average speed between A and B
E) Time to go from B to C is ... time from A to B

I've come up with all these answers and all are wrong. I even narrowed it down to believe that the last 4 answers are "EGLE", but it seems it's wrong.

These are all the possibilities I've come up with, and nope. Still incorrect.

EEGEG

LEGEG

EEGLG

EEGLE

LEGLE

GEGLE

GEGLG

--

Please freaking enlighten me. :cry:

1) T^2 = a^3 so as the semimajor axis is cut in half...the period moves down faster than half (L)
B) they must be the same because equal areas are swept out during equal times. (E)
C) (G) seems you understand this
D) Look at the distance traveled in the same period of time...also, when an orbiting object is closer, its average speed is increased(L)
E) the object's speed slows down as it moves away(G)

I believe this is correct...please correct me if I'm wrong
 
Last edited by a moderator:

Similar threads

  • · Replies 8 ·
Replies
8
Views
2K
  • · Replies 9 ·
Replies
9
Views
3K
Replies
5
Views
2K
  • · Replies 11 ·
Replies
11
Views
5K
Replies
10
Views
3K
Replies
7
Views
6K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 9 ·
Replies
9
Views
2K
Replies
17
Views
4K
  • · Replies 2 ·
Replies
2
Views
6K