Astronomy quiz question: afternoon rising/setting moon

Astronomy 210 Quiz 1, fall semester 2012
Cuesta College, San Luis Obispo, CA

[Version 1]
Which phase will the moon have when it rises at 3:00 PM? Clearly circle your answer below.

Correct answer: (A) (Waxing gibbous).

The moon that rises at 3:00 PM will be highest overhead six hours later, at 9:00 PM, while essentially keeping the same phase (as it would take half a week to go to the next of the eight given phases shown). So the moon that is highest overhead at 9:00 PM would be the waxing gibbous moon (response (A)).

Note that response (C) (waxing crescent) is the phase that the moon would be in if it is highest overhead at 3:00 PM (afternoon).

Section 70160
Exam code: quiz01NaV3
(A) : 1 student
(B) : 2 students
(C) : 8 students
(D) : 0 students
(E) : 3 students
(F) : 1 student
(G) : 0 students
(H) : 1 student

[Version 2]
Which phase will the moon have when it sets at 3:00 PM? Clearly circle your answer below.

Correct answer: (E) (Waning crescent).

The moon that sets at 3:00 PM would have been highest overhead six hours earlier, at 9:00 AM, while essentially keeping the same phase (as it would take half a week to go to the next of the eight given phases shown). So the moon that was highest overhead at 9:00 AM would be the waning crescent moon (response (E)).

Again, note that response (C) (waxing crescent) is the phase that the moon would be in if it is highest overhead at 3:00 PM (afternoon).

Section 70160
Exam code: quiz01NaV3
(A) : 3 students
(B) : 2 students
(C) : 5 students
(D) : 1 student
(E) : 4 students
(F) : 1 student
(G) : 1 student
(H) : 0 students

Success level: 18% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.18