Cuesta College, San Luis Obispo, CA
[Version 1]
Consider Earth, Mars and Venus in their orbits as shown in the diagram below. (This drawing is not to scale, and orbits have been simplified as circles instead of ellipses.)
The motion of Mars in the San Luis Obispo, CA sky is: (A) about to start retrograde motion.
(B) just after completing retrograde motion.
(C) in the middle of retrograde motion.
(D) (None of the above choices, as Mars is not visible in the San Luis Obispo, CA sky.)
Correct answer: (B)
If Earth were aligned along a line between the sun and Mars (i.e., opposition), then Mars would be in the middle of retrograde motion while Earth "laps" Mars. Since Earth is located ahead of Mars, it has already "lapped" Mars, and thus retrograde motion is just been completed.
Section 70160
(A) : 12 students
(B) : 19 students
(C) : 8 students
(D) : 0 students
"Success level": 52% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.64
[Version 2]
Consider Earth, Mars and Venus in their orbits as shown in the diagram below. (This drawing is not to scale, and orbits have been simplified as circles instead of ellipses.)
The motion of Mars in the San Luis Obispo, CA sky is: (A) about to start retrograde motion.
(B) just after completing retrograde motion.
(C) in the middle of retrograde motion.
(D) (None of the above choices, as Mars is not visible in the San Luis Obispo, CA sky.)
Correct answer: (A)
If Earth were aligned along a line between the sun and Mars (i.e., opposition), then Mars would be in the middle of retrograde motion while Earth "laps" Mars. Since Earth is located behind of Mars, it is about to "lap" Mars, and thus retrograde motion is about to start.
Section 70158
(A) : 25 students
(B) : 6 students
(C) : 12 students
(D) : 2 students
"Success level": 60% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.48
No comments:
Post a Comment