B.G.
1. Does this planet obey Kepler’s law? How do you know?
a. Yes, this planet obeys Kepler’s second law because it is a circular orbit and each of the intervals
are of equal distance and time.
2. If you were carefully watching this planet during the entire orbit, would the speed of the planet be
increasing, decreasing, or staying the same? How do you know?
a. The speed of the planet would be staying the same since it moves in a circular orbit centered
around the sun. If the sun were off center in the orbit, this would influence the shape of the orbit
and therefore the speed of the planet.
3. Draw 2 lines: one connecting the planet at Position A to the star and a second line connecting the planet
at Position B to the star. Shade in the triangular area swept out by the planet when traveling from
positions A to B.
a.
4. Pick any two planet positions (C, D, E, F, G, H, I) that you could use to construct a swept out area that
would have approximately the same area as the one you shaded in for Question 3? Shade in the second
swept out area using the planet positions that you chose.
a.
5. How would the time it takes the planet to travel from Position A to Position B compare to the time it
takes to travel between the two positions you selected in Question 4? Explain your reasoning.
a. Assuming that the amount of area covered is the same, it should take the planet the same
amount of time to travel from A to B as it does from D to H.
6. During which of the two time intervals for which you sketched the triangular areas in Questions 3 and 4 is
the distance traveled by the planet greater?
