Download (Draft) Astronomy Ranking Task

Exercise #1
Astronomy Ranking Task:
Kepler’s Laws – Orbital Motion
Description: The figure below shows a comet traveling in an elliptical orbit around the Sun.
The comet is shown as it moves through four different segments of its orbit (labeled A, B, C, and
D). During each segment of the orbit the comet sweeps out the triangular shaped area shaded in
gray. Assume each of the shaded triangular shaped areas has the same size.
A. Ranking Instruction: Rank the time it took (from greatest to least) for the comet to move
along each of the segments (A – D) of the orbit.
Ranking Order: Greatest 1 _______ 2 _______ 3 _______ 4 _______ Least
Or, the time to travel each segment would be the same. ______ (indicate with check mark).
Carefully explain your reasoning for ranking this way:
_____________________________________________________________________________
_____________________________________________________________________________
_____________________________________________________________________________
_____________________________________________________________________________
Copyright © 2005 Conceptual Astronomy and Physics Education Research (CAPER) Team
University of Arizona
B. Ranking Instructions: Rank the distance (from greatest to least) the comet traveled during
each of the segments (A – D) of the orbit.
Ranking Order: Greatest 1 _______ 2 _______ 3 _______ 4 _______ Least
Or, the distance traveled during each segment would be the same. ______ (indicate with check
mark).
Carefully explain your reasoning for ranking this way:
_____________________________________________________________________________
_____________________________________________________________________________
_____________________________________________________________________________
_____________________________________________________________________________
C. Ranking Instructions: Rank the speed (from slowest to fastest) of the comet during each
segment (A – D) of the orbit.
Ranking Order: Slowest 1 _______ 2 _______ 3 _______ 4 _______ Fastest
Or, the speed of the comet during each of the segments would be the same. ______ (indicate
with check mark).
Carefully explain your reasoning for ranking this way:
_____________________________________________________________________________
_____________________________________________________________________________
_____________________________________________________________________________
_____________________________________________________________________________
Copyright © 2005 Conceptual Astronomy and Physics Education Research (CAPER) Team
University of Arizona
Exercise #2
Astronomy Ranking Task:
Kepler’s Laws – Orbital Motion
Description: The figure below shows four locations (A – D) of an asteroid during its elliptical
orbit around the Sun.
Ranking Instructions: Rank the speed (from fastest to slowest) that the asteroid would have at
each of the four locations.
Ranking Order: Fastest 1 ____ 2 ____ 3 ____ 4 ____ Slowest
Or, the orbital speed at each location would be the same. ________ (indicate with check mark).
Carefully explain your reasoning for ranking this way:
_____________________________________________________________________________
_____________________________________________________________________________
_____________________________________________________________________________
_____________________________________________________________________________
Copyright © 2005 Conceptual Astronomy and Physics Education Research (CAPER) Team
University of Arizona
Exercise #3
Astronomy Ranking Task:
Kepler’s Laws – Orbital Motion
Description: The figure below shows a star and five orbiting planets (A – E). Note that planets
A, B and C are in perfectly circular orbits. In contrast, planets D and E have more elliptical
orbits. Note that the closest and farthest distances for the elliptical orbits of planets D and E
happen to match the orbital distances of planets A, B, and C as shown in the figure.
Ranking Instructions: Rank the orbital period (from longest to shortest) of the planets.
Ranking Order: Longest 1 ___ 2 ____ 3 ____ 4 ____ 5 ____ Shortest
Or, the orbital periods of the planets would all be the same. ________ (indicate with check
mark).
Carefully explain your reasoning for ranking this way:
_____________________________________________________________________________
_____________________________________________________________________________
_____________________________________________________________________________
_____________________________________________________________________________
Copyright © 2005 Conceptual Astronomy and Physics Education Research (CAPER) Team
University of Arizona
Exercise #4
Astronomy Ranking Task:
Kepler’s Laws – Orbital Motion
Description: The table below provides a partial list of the orbital periods (in years), and orbital
distances (in AU) for six planets orbiting a one solar-mass star. The mass of each planet is also
provided (in Earth masses).
PLANET
A
B
C
D
E
F
ORBIT DISTANCE
(Semi-major axis in AU)
PERIOD
(Years)
20.0
0.8
3.0
2.0
5.0
3.5
MASS
(Earth Masses)
500
375
100
50
3
0.5
Ranking Instructions: Use the provided information to rank the distance (from farthest to
closest) of the planets (A – F) from the star. Note that it is not necessary, but may be helpful, to
complete the table before making your rankings.
Ranking Order: Farthest 1 ____ 2 ____ 3 ____ 4 ____ 5 ____ 6 ____ Closest
Or, the orbital distance for each of the planets would all be the same. ________ (indicate with
check mark).
Carefully explain your reasoning for ranking this way:
_____________________________________________________________________________
_____________________________________________________________________________
_____________________________________________________________________________
_____________________________________________________________________________
Copyright © 2005 Conceptual Astronomy and Physics Education Research (CAPER) Team
University of Arizona
Exercise #5
Astronomy Ranking Task:
Kepler’s Laws – Orbital Motion
Description: The figure below shows four identical one solar mass stars, and four planets (A –
D) of different masses in circular orbits of various sizes. In each case the mass of the planet is
given in Earth masses and the orbital distance is given in Astronomical Units (AU). Note that
the sizes of the stars and planets, and the orbital distances have not been drawn to scale.
One Earth Mass
Three Earth Masses
1 AU
1 AU
2 AU
2 AU
One Earth Mass
Two Earth Masses
A
B
C
D
Ranking Instructions: Rank the orbital periods (from longest to shortest) of the planets (A – D).
Ranking Order: Longest 1 ___ 2 ____ 3 ____ 4 ____ Shortest
Or, the orbital periods of the planets would all be the same. ________ (indicate with check
mark).
Carefully explain your reasoning for ranking this way:
_____________________________________________________________________________
_____________________________________________________________________________
_____________________________________________________________________________
_____________________________________________________________________________
Copyright © 2005 Conceptual Astronomy and Physics Education Research (CAPER) Team
University of Arizona