20090207

Astronomy quiz question: daylight hours

Astronomy 210 Quiz 1, Spring Semester 2009
Cuesta College, San Luis Obispo, CA

[Version 1]

Consider the position of the Sun at some point on its path across the sky on a certain day, as seen by an observer in San Luis Obispo, CA.

[4.0 points.] On this date, approximately how much time will the Sun be above the horizon, from rise to set?
(A) 10 hours.
(B) 12 hours.
(C) 14 hours.
(D) 30 days.

Section 30674
(A) : 13 students
(B) : 6 students
(C) : 1 student
(D) : 0 students

Correct answer: (A)

For the equinoxes of March or September, the Sun would rise from the east, and set in the west, spending 12 hours above the horizon. If the Sun rises south of east, and sets south of west, it will spend less than 12 hours above the horizon.

[Version 2]

Consider the position of the Sun at some point on its path across the sky on a certain day, as seen by an observer in San Luis Obispo, CA.

[4.0 points.] On this date, approximately how much time will the Sun be above the horizon, from rise to set?
(A) 10 hours.
(B) 12 hours.
(C) 14 hours.
(D) 30 days.

Section 30674
(A) : 7 students
(B) : 6 students
(C) : 4 students
(D) : 0 students

Correct answer: (C)

For the equinoxes of March or September, the Sun would rise from the east, and set in the west, spending 12 hours above the horizon. If the Sun rises north of east, and sets north of west, it will spend more than 12 hours above the horizon.

"Difficulty level": 49% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.90

No comments:

Post a Comment