20100930

Astronomy current events question: Mars' habitable past

Astronomy 210L, Fall Semester 2010
Cuesta College, San Luis Obispo, CA

Students are assigned to read online articles on current astronomy events, and take a short current events quiz during the first 10 minutes of lab. (This motivates students to show up promptly to lab, as the time cut-off for the quiz is strictly enforced!)
Tom Beall, "Mars Was 'Recently' Habitable Planet," September 10, 2010
http://www.skyandtelescope.com/news/wires?id=149649139&c=y
What recent atmospheric data from the NASA Mars Phoenix lander may provide evidence that Mars was habitable enough for life within the past 100 million years?
(A) Fossil remnants of clouds.
(B) Carbon dioxide isotope proportions.
(C) Doppler radar of the upper atmosphere.
(D) Anomalous readings of the sun's intensity.
(E) Reflectance of dust storm particles.

Correct answer: (B)

Student responses
Sections 70178, 70186, 70200
(A) : 1 student
(B) : 25 students
(C) : 2 students
(D) : 1 student
(E) : 0 students

Astronomy current events question: Mars Rover Curiosity power

Astronomy 210L, Fall Semester 2010
Cuesta College, San Luis Obispo, CA

Students are assigned to read online articles on current astronomy events, and take a short current events quiz during the first 10 minutes of lab. (This motivates students to show up promptly to lab, as the time cut-off for the quiz is strictly enforced!)
Courtney O'Connor, "Five Things About NASA's Mars Curiosity Rover," September 16, 2010
http://www.nasa.gov/mission_pages/msl/msl5things20100916.html
In addition to solar panels, the NASA Mars rover Curiosity, planned for arrival on Mars in 2012, will also be powered by:
(A) a nuclear battery.
(B) wind turbines.
(C) methane harvested from soil.
(D) hydrogen harvested from the atmosphere.
(E) refueling from supply depots landing earlier that year.

Correct answer: (A)

Student responses
Sections 70178, 70186, 70200
(A) : 48 students
(B) : 4 students
(C) : 2 students
(D) : 4 students
(E) : 0 students

Astronomy current events question: data mining for trans-Neptunian objects

Astronomy 210L, Fall Semester 2010
Cuesta College, San Luis Obispo, CA

Students are assigned to read online articles on current astronomy events, and take a short current events quiz during the first 10 minutes of lab. (This motivates students to show up promptly to lab, as the time cut-off for the quiz is strictly enforced!)
Astronomy.com editors, "Hubble Data Harvests Distant Solar System Objects," September 14, 2010
http://www.astronomy.com/asy/default.aspx?c=a&id=10220
14 new trans-Neptunian objects (similar to Pluto) were discovered by searching archived data from the NASA Hubble Space Telescope for:
(A) pixels tagged as data errors.
(B) dim infrared spots.
(C) previously uncategorized stars.
(D) changes in Neptune's orbit around the sun.
(E) streaks of light in time-exposure photographs.

Correct answer: (E)

Student responses
Sections 70178, 70186, 70200
(A) : 4 students
(B) : 9 students
(C) : 6 students
(D) : 3 students
(E) : 36 students

Astronomy current events question: lunar bombardment

Astronomy 210L, Fall Semester 2010
Cuesta College, San Luis Obispo, CA

Students are assigned to read online articles on current astronomy events, and take a short current events quiz during the first 10 minutes of lab. (This motivates students to show up promptly to lab, as the time cut-off for the quiz is strictly enforced!)
Astronomy.com editors, "NASA's LRO Exposes the Moon's Complex, Turbulent Youth," September 17, 2010
http://www.astronomy.com/asy/default.aspx?c=a&id=10237
What recent data from the NASA Lunar Reconnaissance Orbiter spacecraft may provide evidence that the moon was bombarded by two distinct populations of asteroids or comets in the past?
(A) Infrared maps of different composition regions.
(B) Chemical tests of soil sample scrapings.
(C) Orbits of small rocky and icy fragments around the moon.
(D) Discovery of new ice-filled craters at the north and south poles.
(E) Detection of gravitational field anomalies.

Correct answer: (A)

Student responses
Sections 70178, 70186, 70200
(A) : 20 students
(B) : 5 students
(C) : 2 students
(D) : 2 students
(E) : 0 students

20100929

Education research: preliminary feedback on flashcards and online reading assignments (Cuesta College, Astronomy 210, Fall Semester 2010)

Cuesta College students taking Astronomy 210 (introductory astronomy) at Cuesta College, San Luis Obispo, CA use flashcards to engage in peer-interaction ("think-pair-share") discussion questions during lecture, and complete weekly online reading assignments (hosted by SurveyMonkey.com), where they answer questions based on reading their textbook, material covered in previous lectures, opinion questions, and/or asking (anonymous) questions or making (anonymous) comments.

Through the fifth week of instruction, students were given the opportunity to evaluate the instructional components of the course, and the use of flashcards and online reading assignments in an online "Learning Resource Survey" hosted by SurveyMonkey.com. Questions from section II are adapted from the Student Assessment of Learning Gains (SALG) survey (developed by Elaine Seymour, Wisconsin Center for Education Research, University of Wisconsin-Madison), and questions from section III (III.1, III.3, III.5, and III.7) were adapted from a "Clicker Attitude Survey" (N. W. Reay, Lei Bao, and Pengfei Li, Physics Education Research Group, Ohio State University).

These are the complete survey results. Analysis will be forthcoming after more data has been compiled from future semesters. Values for the mean and standard deviations are given next to the modal response category for each question. Note that the order of questions within sections II, III, and V were randomly scrambled for each student.
Learning Resource Survey
Cuesta College
Astronomy 210 Fall Semester 2010 sections 70158, 70160
(N = 35)

I. In order to receive credit for completing this survey,
first enter your first and last name below:
____


II. How much did each of the following aspects of the class help
your learning?

II.1 Lecture by instructor.
1. Strongly disagree 0 :
2. Disagree 1 : *
3. Neutral 5 : *****
4. Agree 17 : ***************** [4.1 +/- 0.8]
5. Strongly agree 12 : ************

II.2 Working in groups on in-class activities.
1. Strongly disagree 0 :
2. Disagree 1 : *
3. Neutral 11 : ***********
4. Agree 14 : **************
5. Strongly agree 9 : ********* [3.9 +/- 0.8]

II.3 Using flashcards to participate in class.
1. Strongly disagree 3 : ***
2. Disagree 1 : *
3. Neutral 6 : ******
4. Agree 13 : ************* [3.9 +/- 1.2]
5. Strongly agree 12 : ************

II.4 Reading the textbook.
1. Strongly disagree 1 : *
2. Disagree 2 : **
3. Neutral 12 : ************ [3.6 +/- 0.9]
4. Agree 16 : ****************
5. Strongly agree 4 : ****

II.5 Interacting with other students during class.
1. Strongly disagree 1 : *
2. Disagree 1 : *
3. Neutral 10 : **********
4. Agree 17 : ***************** [3.7 +/- 0.9]
5. Strongly agree 6 : ******

II.6 Interacting with other students outside of class.
1. Strongly disagree 3 : ***
2. Disagree 5 : *****
3. Neutral 15 : *************** [3.1 +/- 1.1]
4. Agree 8 : ********
5. Strongly agree 4 : ****

II.7 Online reading assignments.
1. Strongly disagree 2 : **
2. Disagree 3 : ***
3. Neutral 12 : ************ [3.5 +/- 1.1]
4. Agree 13 : *************
5. Strongly agree 5 : *****

III. Answer the following statements which may or may not describe
your beliefs about the use of flashcards in this class.

III.1 I like using flashcards.
1. Strongly disagree 2 : **
2. Disagree 5 : *****
3. Neutral 4 : ****
4. Agree 18 : ****************** [3.6 +/- 1.1]
5. Strongly agree 6 : ******

III.2 Flashcards helped me understand lectures better.
1. Strongly disagree 2 : **
2. Disagree 4 : ****
3. Neutral 4 : ****
4. Agree 18 : ****************** [3.7 +/- 1.1]
5. Strongly agree 7 : *******

III.3 I would recommend using flashcards in future semesters of this class.
1. Strongly disagree 1 : *
2. Disagree 3 : ***
3. Neutral 5 : *****
4. Agree 16 : **************** [3.9 +/- 1.0]
5. Strongly agree 10 : **********

III.4 I will avoid other classes using flashcards in future semesters.
1. Strongly disagree 9 : *********
2. Disagree 16 : **************** [2.1 +/- 1.7]
3. Neutral 6 : ******
4. Agree 3 : ***
5. Strongly agree 0 :

III.5 Flashcards were a positive experience.
1. Strongly disagree 0 :
2. Disagree 6 : ******
3. Neutral 6 : ******
4. Agree 15 : *************** [3.7 +/- 1.0]
5. Strongly agree 8 : ********

III.6 Too much time in class was spent using flashcards.
1. Strongly disagree 8 : ********
2. Disagree 18 : ****************** [2.1 +/- 1.5]
3. Neutral 7 : *******
4. Agree 1 : *
5. Strongly agree 1 : *

III.7 Too many flashcard questions were asked.
1. Strongly disagree 6 : ******
2. Disagree 19 : ******************* [2.3 +/- 1.4]
3. Neutral 6 : ******
4. Agree 2 : **
5. Strongly agree 2 : **

III.8 Using flashcards was difficult.
1. Strongly disagree 10 : **********
2. Disagree 16 : **************** [2.1 +/- 1.9]
3. Neutral 5 : *****
4. Agree 2 : **
5. Strongly agree 1 : *

IV. (Optional.) Please type in any comments you may have regarding
the use of flashcards in Astronomy 210.
The following are all of the student responses to this question, verbatim and unedited.
":)"

"I think it's a good way for the teacher to gauge the students' understanding of the concepts presented in class."

"I think using flashcards is helpful because it reinforces what's being taught, and we are asked some questions that are likely to be on the test/quizzes. Also, we answer to some extent of anonymity which takes the pressure off."

"I enjoy it way more than working in groups. :P"

"I think using flash cards have helped me a lot when it comes to understanding lectures"

"A... no wait, D."

"i really enjoy the use of flash cards they help me better understand what is going on in the class."

"I like the use of flashcards and having the opportunity to explain your position."

"I think the flash cards are a cop out for the teacher to do the job of explaining... I don't think people learn by having a multiple choice question presented, a flash card flash fest, and then having someone answer... The people who understand answer but most times I still don't know why and feel like I need to learn the material all by myself. I read the chapters which is where I feel like have learned the most in this class."

"i think its a good way to learn things if we dont understand it you will explain it to us also with ohter student in the class answering and explaing it in there way helps also..."

"Flashcards are a good way to keep students focused, the only downside is that we as students can not see the majority of the classes' answer."

"The flashcards were new and different to me when I first started the class, but now I have learned to like them."

"I think they are good way for the student to find out if they know something before a test, and its a good indicator for the proffesor about how the class is doing on different subjects."

"I really don't mind the flashcards."

"I only like the way flashcards are used in this class. Other classes use them to put students on the spot and they are unhelpful in other classes."

"Unless the answers are reviewed in class, I don't understand the use of the flashcards. If they are used, the professor needs to go over them thoroughly and slowly. Rushing through them makes it really confusing."

"Ireally liked them."

"Very helpful for exams and correcting misunderstandings."

"Flashcards are good, just the questions are really hard at times and I wish the teacher would explain it himself instead of having us students discuss it with each other."

"Flash cards are great because they make everyone answer the questions rather than just the people who already know the right answer. Also, they are much more efficient than the clickers that we use in other classes in my opinion.
I've never used flashcards in any other class before this one and I really like it."

"I liked the use of flashcards in class because if we were wrong we were able to find out from our classmates the best possible answer."

"i really like the flashcards they are really useful."

"Flashcards are difficult... I'm always worried when we have to use them"


V. Answer the following statements which may or may not describe 
your beliefs about the use of the online reading assignments in this class.

V.1 I like working on the online reading assignments.
1. Strongly disagree 2 : **
2. Disagree 4 : ****
3. Neutral 10 : **********
4. Agree 16 : **************** [3.4 +/- 1.0]
5. Strongly agree 3 : ***

V.2 Online reading assignments helped me understand lectures better.
1. Strongly disagree 1 : *
2. Disagree 4 : ****
3. Neutral 13 : *************
4. Agree 15 : *************** [3.4 +/- 1.0]
5. Strongly agree 2 : **

V.3 I would recommend using online reading assignments in future semesters of this class.
1. Strongly disagree 1 : *
2. Disagree 1 : *
3. Neutral 10 : **********
4. Agree 19 : ******************* [3.7 +/- 0.8]
5. Strongly agree 4 : ****

V.4 I will avoid other classes using online reading assignments in future semesters.
1. Strongly disagree 8 : ********
2. Disagree 22 : ********************** [1.9 +/- 1.4]
3. Neutral 5 : *****
4. Agree 0 :
5. Strongly agree 0 :

V.5 Online reading assignments were a positive experience.
1. Strongly disagree 0 :
2. Disagree 2 : **
3. Neutral 10 : **********
4. Agree 18 : ****************** [3.7 +/- 0.8]
5. Strongly agree 5 : *****

V.6 Too much time outside of class was spent working on online reading assignments.
1. Strongly disagree 10 : **********
2. Disagree 15 : *************** [2.0 +/- 1.8]
3. Neutral 9 : *********
4. Agree 1 : *
5. Strongly agree 0 :

V.7 Too many online reading assignment questions were asked.
1. Strongly disagree 7 : *******
2. Disagree 22 : ********************** [2.0 +/- 1.3]
3. Neutral 5 : *****
4. Agree 0 :
5. Strongly agree 1 : *

V.8 Completing the online reading assignments was difficult.
1. Strongly disagree 11 : *********** [2.1 +/- 2.0]
2. Disagree 13 : *************
3. Neutral 9 : *********
4. Agree 2 : **
5. Strongly agree 0 :

VI. (Optional.) Please type in any comments you may have regarding
the online reading assignments in Astronomy 210.
The following are all of the student responses to this question, verbatim and unedited.
":)"

"I think it's a pretty good idea to do the online reading assignments."

"I don't think online reading assignments really helped me at all thus far in the semester. We're quizzed on the chapters we havent even gone over yet in class, so it's all pretty much a guess. It's not very time consuming or neccessarily difficult, but I don't see the relevance or importance of it.
yay!"

"The online reading assignments were chalenging but it helped me understand the material"

"There were no cake."

"the online reading assignments sometimes help but other times i don't recall what was on the online reading assignment.
I would prefer online questions that pertain to the work we are currently doing in class, not on future subjects that we may not even get to in the next lecture."

"They are easy to complete and it is nice not having a bunch of homework; however it doesn't really require the student to do much or learn because they are pass or fail."

"the onlie reading assingments are nice they are just like a little summary of what we should have read it also helps me kind of know waht the main points where if that what you are pulling out of it. i dont think they are to much or do i think there is to many questions. they are a easy way to get thoes extra points to help if u completly bomb a test these will help in the end run."

"They are easy and simple, but challenge me to think a little bit."

"The online reading assignments have really helped me in learning more about astronomy."

"I like the online reading assignments better than other homework."

"These online reading assignments are very helpful and an easy way to do homework."

"Answers to these questions would be useful if they are discussed in the following class."

"They were good, and really make you read the book."

"Good amount and not an overload to remember information."

"Online reading assignments are pretty easy, and its a lot better doing in on the keyboard rather than doing questions out of the book."

"They're pretty easy, but they require reading the textbook to complete them anyway."

"I think it is awesome that you realize we are busy with other classes as well as yours so i like that theres not a billion questions."

"The only problem I have with the assignments was it was hard to get my computer to recognize the site."

"I really don't know what to think about the reading assignments."

20100928

Astronomy current events question: ICESat crash

Astronomy 210L, Fall Semester 2010
Cuesta College, San Luis Obispo, CA

Students are assigned to read online articles on current astronomy events, and take a short current events quiz during the first 10 minutes of lab. (This motivates students to show up promptly to lab, as the time cut-off for the quiz is strictly enforced!)
Clay Dillow, "Undergrads at Colorado Crash a NASA Satellite Into The Ocean," September 1, 2010
http://www.popsci.com/technology/article/2010-09/undergrads-colorado-kick-school-week-crashing-satellite
The NASA Ice, Cloud, and Land Elevation Satellite (ICESat) was recently __________ by undergraduate students at the University of Colorado at Boulder.
(A) illegally hacked into.
(B) deliberately ordered to crash.
(C) accidentally shut down.
(D) uploaded with a new operating system.
(E) named unofficial school mascot.

Correct answer: (B)

Student responses
Sections 70178, 70186, 70200
(A) : 0 students
(B) : 56 students
(C) : 5 students
(D) : 3 students
(E) : 0 students

Astronomy current events question: Viking lander results

Astronomy 210L, Fall Semester 2010
Cuesta College, San Luis Obispo, CA

Students are assigned to read online articles on current astronomy events, and take a short current events quiz during the first 10 minutes of lab. (This motivates students to show up promptly to lab, as the time cut-off for the quiz is strictly enforced!)
Astronomy.com editors, "Missing Piece Inspires New Look at Mars Puzzle," September 7, 2010
http://www.astronomy.com/asy/default.aspx?c=a&id=10194
Scientists recently proposed that the NASA Viking landers had detected organic compounds in martian soil, rather than from:
(A) self contamination.
(B) solar flares.
(C) cosmic rays.
(D) dry ice geysers.
(E) acid rain chemicals.

Correct answer: (A)

Student responses
Sections 70178, 70186, 70200
(A) : 46 students
(B) : 5 students
(C) : 3 students
(D) : 7 students
(E) : 3 students

Astronomy current events question: cosmic pinwheel

Astronomy 210L, Fall Semester 2010
Cuesta College, San Luis Obispo, CA

Students are assigned to read online articles on current astronomy events, and take a short current events quiz during the first 10 minutes of lab. (This motivates students to show up promptly to lab, as the time cut-off for the quiz is strictly enforced!)
Kelly Beatty, "A Ghostly Cosmic Pinwheel," September 9, 2010
http://www.skyandtelescope.com/community/skyblog/newsblog/102593154.html
The Hubble Space Telescope image of IRAS 23166+1655 resembles a "cosmic pinwheel," apparently created by:
(A) a star falling into a black hole.
(B) a telescope mirror defect.
(C) a dying star with a binary companion.
(D) colliding galaxies.
(E) planetary formation.

Correct answer: (C)

Student responses
Sections 70178, 70186, 70200
(A) : 0 students
(B) : 1 student
(C) : 49 students
(D) : 4 students
(E) : 10 students

20100926

Found physics: pocket microscopes

100910-1190133
http://www.flickr.com/photos/waiferx/4978228328/
Originally uploaded by Waifer X

Pocket microscopes, 30x, 100x. Photo by Cuesta College Physical Sciences Division instructor Dr. Patrick M. Len.

20100925

Overheard: think-pair-share flashcard shaking

Astronomy 210, Fall Semester 2010
Cuesta College, San Luis Obispo, CA

(Overheard at the end of a think-pair-share flashcard cycle, when students were apparently unanimously voting for the correct answer, but did not seem very confident in their responses.)

Instructor: (Looking at nearly unanimous student flashcard results.) "Wait: remember, even if you think you have the correct answer--if you're just guessing, or if you aren't comfortable being asked to explain your answer, choose '(E) I'm lost, and don't know how to answer this.'"

Students: (No one changes their flashcard answers.)

Instructor: "Okay. If you're really confident of your answers, then shake your flashcards... (Beat.) Like a Polaroid(TM) picture."

Students: (Only a third of the class shakes their flashcards.)

20100924

Physics quiz question: telescope objective lens image

Physics 205B Quiz 2, Fall Semester 2010
Cuesta College, San Luis Obispo, CA

Cf. Giambattista/Richardson/Richardson, Physics, 2/e, Multiple-Choice Question 24.1

The objective lens of a telescope produces a:
(A) real image between the objective lens and eyepiece lens.
(B) real image in front of the objective lens.
(C) virtual image between the objective lens and eyepiece lens.
(D) virtual image in front of the objective lens.

Correct answer: (A)

The objective lens of a telescope, for an object at infinity, produces a real (inverted) image at its primary focal point, which will be located between the objective lens and the eyepiece lens.

Student responses
Section 70856
(A) : 9 students
(B) : 1 student
(C) : 0 students
(D) : 1 student

Success level: 82%
Discrimination index (Aubrecht & Aubrecht, 1983): 0.40

20100923

Physics quiz question: refractor telescope

Physics 205B Quiz 2, Fall Semester 2010
Cuesta College, San Luis Obispo, CA

Cf. Giambattista/Richardson/Richardson, Physics, 2/e, Problem 24.51

The objective lens of an astronomical telescope forms an image of a distant object at the focal point of the eyepiece, which has a focal length of +1.5 cm. If the two lenses are 80.0 cm apart, what is the angular magnification?
(A) –54.
(B) –52.
(C) –17.
(D) –4.8.

Correct answer: (B)

The objective lens of a telescope, for an object at infinity, produces a real image at its primary focal point. An eyepiece, used as a simple magnifier by a relaxed eye, will need to have this intermediate real image at its second focal point in order to achieve the maximum angular magnification. This means that the primary focal point of the objective lens is located at the secondary focal point of the eyepiece, and thus the separation distance L between the lenses is:

L = 80.0 cm = f_o + f_e.

Since the focal length of the eyepiece is given (f_e = +1.5 cm), then the focal length of the objective can be substituted in using the above information into the angular magnification equation for a telescope:

M = -f_o/f_e = -(L - f_e)/f_e = -(80.0 cm - (+1.5 cm))/(+1.5 cm) = -52.333... = -52,

to two significant figures.

Response (A) is -(L + f_e)/f_e; response (C) is -N/f_e (where N is the nominal near point of 0.25 m); response (D) is -L*f_e/N.

Student responses
Section 70856
(A) : 2 students
(B) : 7 students
(C) : 1 student
(D) : 1 student

Success level: 64%
Discrimination index (Aubrecht & Aubrecht, 1983): 0.80

20100922

Physics quiz question: simple magnifier

Physics 205B Quiz 2, fall semester 2010
Cuesta College, San Luis Obispo, CA

Cf. Giambattista/Richardson/Richardson, Physics, 2/e, Problem 24.29

A Physics 205B student would like to use a +10.0 D converging lens as a simple magnifier. What is the angular magnification of this lens as used by a relaxed eye?
(A) +0.40.
(B) +2.5.
(C) +10.
(D) +40.

Correct answer (highlight to unhide): (C)

The focal length of the lens (in m) is the inverse of the refractive power P (in diopters, D, or equivalently m–1):

f = 1/P.

The angular magnification of a converging lens, used as a simple magnifier (and a relaxed eye) is given by:

M = N/f,

where N is the nominal near point of 0.25 m. Thus the angular magnification is:

M = N/f = N·P = (0.25 m)·(+10.0 m–1) = +2.5.

(Response (A) is 1/(N·P); response (C) is P; and response (D) is P/N.)

Student responses
Section 70856
(A) : 1 student
(B) : 0 students
(C) : 9 students
(D) : 1 student

Success level: 82%
Discrimination index (Aubrecht & Aubrecht, 1983): 0.40

20100921

Physics quiz question: contact lens for myopia

Physics 205B Quiz 2, Fall Semester 2010
Cuesta College, San Luis Obispo, CA

Cf. Giambattista/Richardson/Richardson, Physics, 2/e, Example 24.4, Practice Problem 24.4

A Physics 205B student with an uncorrected far point of 3.5 m uses contact lenses. When a contact lens is used by this student to look very far away, the object for the eye is an intermediate virtual image produced by the contact lens. This intermediate virtual image is located:
(A) at ∞.
(B) 0.25 m from the eye.
(C) at the uncorrected far point of the eye.
(D) at the uncorrected near point of the eye.

Correct answer: (C)

The contact lens must produce a virtual (erect) image at a distance that the eye can see. Thus for a contact lens that fully corrects for myopia (nearsightedness), for objects at p_contacts = +∞, the contact lens must create a virtual image at a distance of q_contacts = –3.5 m, which is at the uncorrected far point of the eye.

Student responses
Section 70856
(A) : 0 students
(B) : 1 student
(C) : 9 students
(D) : 1 student

Success level: 82%
Discrimination index (Aubrecht & Aubrecht, 1983): 0.40

20100920

Physics quiz question: two lens system

Physics 205B Quiz 2, Fall Semester 2010
Cuesta College, San Luis Obispo, CA

Cf. Giambattista/Richardson/Richardson, Physics, 2/e, Problem 24.1

An upright object is placed 10.0 cm to the left of a converging lens with focal length +15.0 cm. A second converging lens with focal length +4.0 cm is placed 5.0 cm to the right of the first lens. Where is the final image located?
(A) To the left of the first lens.
(B) Between the first lens and second lens.
(C) To the right of the second lens.
(D) (No image would be produced.)

Correct answer: (C)

The object is placed within the primary focal point of the first converging lens, which will result in a virtual image, also located to the left of this lens. This virtual image created by the first lens will then be the object for the second lens, and since the object distance for the second lens is outside its primary focal point, the resulting final image will be a real image, located to the right fo the second lens.

Student responses
Section 70856
(A) : 0 students
(B) : 1 student
(C) : 9 students
(D) : 1 student

Success level: 82%
Discrimination index (Aubrecht & Aubrecht, 1983): 0.20

20100919

Astronomy quiz question: finding Mars, Venus (2)

Astronomy 210 Quiz 2, Fall Semester 2010
Cuesta College, San Luis Obispo, CA

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.)

[Version 1]
What is seen by an observer in San Luis Obispo, CA at sunrise (6 AM)?
(A) Only Venus.
(B) Only Mars.
(C) Both Venus and Mars.
(D) (None of the above choices, as both Venus and Mars would not be visible in the San Luis Obispo, CA sky at this time.)

Correct answer: (B)

At 6 AM, Venus would be below the observer's horizon, while Mars would be visible above the west horizon as the sun rises in the east horizon.

Section 70158
(A) : 10 students
(B) : 8 students
(C) : 3 students
(D) : 1 student

[Version 2]
What is seen by an observer in San Luis Obispo, CA at sunset (6 PM)?
(A) Only Venus.
(B) Only Mars.
(C) Both Venus and Mars.
(D) (None of the above choices, as both Venus and Mars would not be visible in the San Luis Obispo, CA sky at this time.)

Correct answer: (A)

At 6 PM, Mars would be below the observer's horizon, while Venus would be visible above the west horizon as the sun sets in the west horizon.

Section 70158
(A) : 12 students
(B) : 7 students
(C) : 2 students
(D) : 2 students

"Success level": 50% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.55

20100918

Astronomy quiz question: finding Mars, Venus (1)

Astronomy 210 Quiz 2, Fall Semester 2010
Cuesta College, San Luis Obispo, CA

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.)

[Version 1]
What is seen by an observer in San Luis Obispo, CA at sunrise (6 AM)?
(A) Only Venus.
(B) Only Mars.
(C) Both Venus and Mars.
(D) (None of the above choices, as both Venus and Mars would not be visible in the San Luis Obispo, CA sky at this time.)

Correct answer: (A)

At 6 AM, Mars would be below the observer's horizon, while Venus would be visible above the east horizon as the sun rises in the east horizon.

Section 70160
(A) : 8 students
(B) : 3 students
(C) : 5 students
(D) : 4 students

[Version 2]
What is seen by an observer in San Luis Obispo, CA at sunset (6 PM)?
(A) Only Venus.
(B) Only Mars.
(C) Both Venus and Mars.
(D) (None of the above choices, as both Venus and Mars would not be visible in the San Luis Obispo, CA sky at this time.)

Correct answer: (B)

At 6 PM, Venus would be below the observer's horizon, while Mars would be visible above the east horizon as the sun sets in the west horizon.

Section 70160
(A) : 3 students
(B) : 11 students
(C) : 3 students
(D) : 2 students

"Success level": 53% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.55

20100917

Astronomy quiz question: retrograde motion

Astronomy 210 Quiz 2, Fall Semester 2010
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

20100915

Astronomy current events question: dusty protoplanetary disks

Astronomy 210L, Fall Semester 2010
Cuesta College, San Luis Obispo, CA

Students are assigned to read online articles on current astronomy events, and take a short current events quiz during the first 10 minutes of lab. (This motivates students to show up promptly to lab, as the time cut-off for the quiz is strictly enforced!)
Whitney Clavin, "Pulverized Planet Dust May Lie Around Double Stars," August 23, 2010
http://www.nasa.gov/mission_pages/spitzer/news/spitzer20100823.html
Hot dusty disks surrounding close binary star systems observed by the Spitzer Space Telescope may be caused by:
(A) disrupted star formation.
(B) magnetic field storms.
(C) planets that have collided.
(D) telescope software glitches.
(E) lack of liquid coolant.

Correct answer: (C)

Student responses
Sections 70178, 70186, 70200
(A) : 7 students
(B) : 9 students
(C) : 46 students
(D) : 0 students
(E) : 1 student

Astronomy current events question: Kepler-9 planetary transits

Astronomy 210L, Fall Semester 2010
Cuesta College, San Luis Obispo, CA

Students are assigned to read online articles on current astronomy events, and take a short current events quiz during the first 10 minutes of lab. (This motivates students to show up promptly to lab, as the time cut-off for the quiz is strictly enforced!)
Alan MacRobert, "Two Exoplanets in an Interactive Dance," August 26, 2010
http://www.skyandtelescope.com/news/101571373.html
How have NASA researchers determined that two planets orbiting the sun-like star Kepler 9 are gravitationally interacting with each other?
(A) Both planets are moving farther out away from their star.
(B) The time for each planet to pass in front of their star changes slightly.
(C) One planet loses hydrogen, while the other gains hydrogen.
(D) Predictions from Einstein's general theory of relativity.
(E) The star's rotation rate changes slightly.

Correct answer: (B)

Student responses
Sections 70178, 70186, 70200
(A) : 3 students
(B) : 46 students
(C) : 4 students
(D) : 0 students
(E) : 11 students

Astronomy current events question: pre-Chicxulub impact event

Astronomy 210L, Fall Semester 2010
Cuesta College, San Luis Obispo, CA

Students are assigned to read online articles on current astronomy events, and take a short current events quiz during the first 10 minutes of lab. (This motivates students to show up promptly to lab, as the time cut-off for the quiz is strictly enforced!)
Kelly Beatty, "The Dinosaurs Got a Warning Shot," August 31, 2010
http://www.skyandtelescope.com/news/101880488.html
__________ obtained by Scottish scientists buried in sedimentary layers in a recently-discovered impact crater indicate that life may have recovered quickly afterwards, until the later Chicxulub impact that killed the dinosaurs.
(A) Alien spores.
(B) Iridium samples.
(C) Small primitive mammal fossils.
(D) Lack of dinosaur fossils.
(E) Plant material.

Correct answer: (E)

Student responses
Sections 70178, 70186, 70200
(A) : 1 student
(B) : 3 students
(C) : 9 students
(D) : 4 students
(E) : 46 students

20100914

Overheard: think-pair-share fail

Astronomy 210, Fall Semester 2010
Cuesta College, San Luis Obispo, CA

(Overheard at the end of a think-pair-share flashcard cycle, when students were not able to come to a consensus after explaining to each other in pairs why/how they thought their answers were correct.)

Instructor: (Looking at student flashcard results.) "You guys...suck!"

Students: "What?!?"

Instructor: "And you know who's to blame?"

(Beat.)

Instructor: "Your astronomy teacher."

20100913

Astronomy current events question: mud volcanoes on Mars

Astronomy 210L, Fall Semester 2010
Cuesta College, San Luis Obispo, CA

Students are assigned to read online articles on current astronomy events, and take a short current events quiz during the first 10 minutes of lab. (This motivates students to show up promptly to lab, as the time cut-off for the quiz is strictly enforced!)
Anuradha K. Herath, "Mud Volcanoes on Mars," August 19, 2010
http://www.astrobio.net/exclusive/3586/mud-volcanoes-on-mars
According to NASA researchers, __________ may be evidence of mud volcanoes on Mars.
(A) underground seismic activity.
(B) lack of above ground water.
(C) images taken by the Mars Reconnaissance Orbiter.
(D) samples drilled by the Mars Exploration Rover Opportunity.
(E) Mars Exploration Rover Spirit sinking into mud.

Correct answer: (C)

Student responses
Sections 70178, 70186, 70200
(A) : 16 students
(B) : 0 students
(C) : 46 students
(D) : 5 students
(E) : 2 students

20100912

Astronomy current events question: shrinking moon

Astronomy 210L, Fall Semester 2010
Cuesta College, San Luis Obispo, CA

Students are assigned to read online articles on current astronomy events, and take a short current events quiz during the first 10 minutes of lab. (This motivates students to show up promptly to lab, as the time cut-off for the quiz is strictly enforced!)
Astronomy.com editors, "Lunar Reconnaissance Orbiter Reveals Incredible Shrinking Moon," August 20, 2010
http://www.astronomy.com/asy/default.aspx?c=a&id=10155
NASA's Lunar Reconnaissance Orbiter recently observed __________, which may indicate that the moon shrank recently, and may still be shrinking today.
(A) sizes of craters decreasing over time.
(B) fresh lava flows.
(C) mud volcanoes.
(D) cliffs that cut across small craters.
(E) growing sinkholes.

Correct answer: (A)

Student responses
Sections 70178, 70186, 70200
(A) : 5 students
(B) : 0 students
(C) : 0 students
(D) : 27 students
(E) : 2 students

20100911

Astronomy current events question: HD 10180 planetary system

Astronomy 210L, Fall Semester 2010
Cuesta College, San Luis Obispo, CA

Students are assigned to read online articles on current astronomy events, and take a short current events quiz during the first 10 minutes of lab. (This motivates students to show up promptly to lab, as the time cut-off for the quiz is strictly enforced!)
Kelly Beatty, "One Star, Seven Planets," August 24, 2010
http://www.skyandtelescope.com/news/101410964.html
The recently discovered planetary system around the star HD 10180:
(A) contains the largest number of exoplanets in a single system.
(B) survived a recent nova explosion of HD 10180.
(C) emits radio signals of possible technological origin.
(D) matches descriptions found in ancient Mayan writings.
(E) may be entirely formed from dark matter.

Correct answer: (A)

Student responses
Sections 70178, 70186, 70200
(A) : 31 students
(B) : 2 students
(C) : 1 student
(D) : 0 students
(E) : 1 student

20100910

Cuesta College North County campus star party

100909-1190130
http://www.flickr.com/photos/waiferx/4975512415/
Originally uploaded by Waifer X

Cuesta College Astronomy 210L students and guest during a North County campus star party. Photo by Cuesta College Physical Sciences Division instructor Dr. Patrick M. Len.

Sights seen:
Venus
Mars
Mizar A/B
Alcor
Epsilon Lyrae
Jupiter

Physics quiz question: possible total internal reflection?

Physics 205B Quiz 1, fall semester 2010
Cuesta College, San Luis Obispo, CA

Cf. Giambattista/Richardson/Richardson, Physics, 2/e, Comprehensive Problem 23.78

A beam of light strikes the interface between glycerin (index of refraction[*] 1.473) and air (index of refraction 1.000), with an incident angle 44.0°. (Drawing is not to scale.) As a result, this light is:
(A) reflected back into glycerin.
(B) transmitted into air.
(C) (Both of the above choices.)
(D) (Not enough information is given.)

[*] physics.info/refraction/.

Correct answer (highlight to unhide): (A)

The critical angle for light incident on a glycerine-air interface is given by:

θc = sin–1(n2/n2) = sin–1(1.000/1.473) = 42.76°.

Since the incident angle of 44.0° is greater than the critical angle, then the light in glycerin will experience total internal reflection back down into the glycerin, with none of it transmitted out into air.

Student responses
Section 70856
(A) : 12 students
(B) : 0 students
(C) : 1 student
(D) : 0 students

Success level: 92%
Discrimination index (Aubrecht & Aubrecht, 1983): 0.13

20100909

Physics quiz question: unpolarized light through two polarizers

Physics 205B Quiz 1, fall semester 2010
Cuesta College, San Luis Obispo, CA

Cf. Giambattista/Richardson/Richardson, Physics, 2/e, Problem 22.45


Unpolarized light is incident on two ideal polarizers with polarization axes turned 20° to one another. What is the fraction of the original unpolarized light intensity transmitted through the second polarizer?
(A) 0.22.
(B) 0.25.
(C) 0.44.
(D) 0.47.

Correct answer: (C)

Half of the original unpolarized light passes through the first polarizer. Of that, the fraction of light (now polarized vertically) that passes through the second polarizer with a polarization axis that is is tilted 20° with respect to this vertically polarized light is (cos(20°))2 = 0.88, such that the fraction of the original unpolarized light that passes through both the first and second polarizers is 0.5·(cos(20°))2 = 0.44.

Response (A) is (0.5·cos(20°))^2; response (B) is 0.52, and response (D) is 0.5·cos(20°).

Student responses
Section 70856
(A) : 1 student
(B) : 1 student
(C) : 11 students
(D) : 0 students

Success level: 85%
Discrimination index (Aubrecht & Aubrecht, 1983): 0.25

20100908

Physics quiz question: "hellameter"

Physics 205B Quiz 1, Fall Semester 2010
Cuesta College, San Luis Obispo, CA

Cf. Giambattista/Richardson/Richardson, Physics, 2/e, Problem 22.17

How long does it take light to travel 1 Hm (1 "hellameter" = 10^27 m) in vacuum?
(A) 3.33e–36 s.
(B) 3.00e–19 s.
(C) 3.33e+18 s.
(D) 3.00e+35 s.

Correct answer: (C)

The speed of light in vacuum is c = 3.00e+8 m/s, and the relation between speed, distance, and elapsed time is:

c = ∆x/∆t,

such that solving for time gives:

∆t = (∆x)/c = (3.00e+8 m/s)/(1e+27 m) = 3.33e+18 s.

Response (A) is 1/(c*∆x); response (B) is c/∆x, and response (D) is c*∆x.

Student responses
Section 70856
(A) : 0 students
(B) : 3 students
(C) : 7 students
(D) : 3 students

Success level: 54%
Discrimination index (Aubrecht & Aubrecht, 1983): 0.75

20100907

Astronomy quiz question: cause of moon phases

Astronomy 210 Quiz 1, Fall Semester 2010
Cuesta College, San Luis Obispo, CA

What causes the different phases of the moon?
(A) Different amounts of the far and near sides of the moon as seen from Earth.
(B) Different amounts of the day and night sides of the moon as seen from Earth.
(C) Earth blocks light from the sun, casting a shadow on the moon.
(D) The slow, gradual rotation of the moon about its own axis.

Correct answer: (B)

Response (C) is the cause of lunar eclipses, responses (A) and (C) are related to the synchronously tidal-locked rotation of the moon as it keeps (nearly) the same side facing towards Earth.

Section 70158
(A) : 1 student
(B) : 9 students
(C) : 21 students
(D) : 12 students
(No response) : 1 student

"Success level": 25% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.20

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20100906

Astronomy quiz question: vernal equinox

Astronomy 210 Quiz 1, Fall Semester 2010
Cuesta College, San Luis Obispo, CA

An observer in San Luis Obispo, CA watches the sunrise in late March. On this day, approximately how much time is the sun above the horizon, from rise to set?
(A) 10 hours.
(B) 12 hours.
(C) 14 hours.
(D) 24 hours.

Correct answer: (B)

On the vernal (spring) equinox in late March, there are 12 hours of daylight and 12 hours of night.

Section 70158
(A) : 6 students
(B) : 35 students
(C) : 3 students
(D) : 0 students

"Success level": 82% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.50

20100905

Astronomy quiz question: rotation

Astronomy 210 Quiz 1, Fall Semester 2010
Cuesta College, San Luis Obispo, CA

Earth's __________ causes the stars to move across the celestial sphere over several hours, as seen by an observer in San Luis Obispo, CA.
(A) rotation.
(B) revolution.
(C) precession.
(D) tilt.

Correct answer: (A)

Earth rotation on its axis causes the stars move across the sky, taking approximately 24 hours (23.93447 hours) to return to the same location.

Section 70158
(A) : 39 students
(B) : 2 students
(C) : 1 student
(D) : 2 students

"Success level": 89% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.25

20100904

Astronomy quiz question: sidereal cycle

Astronomy 210 Quiz 1, Fall Semester 2010
Cuesta College, San Luis Obispo, CA

An observer in San Luis Obispo, CA notices that the constellations Camelopardalis, Perseus, and Aries are just above the northeast horizon at 9:00 PM on August 31. Approximately how much time elapses until these three constellations will again be in the same position in the sky, just above the northeast horizon?
(A) 12 hours.
(B) 18 hours.
(C) 24 hours.
(D) 30 days.

Correct answer: (C)

It will take approximately 24 hours (23.93447 hours) for the stars to return to the same location in the sky. (Note that students were allowed to use their starwheels (planispheres) for this quiz.)

Section 70160
(A) : 9 students
(B) : 0 students
(C) : 28 students
(D) : 4 students

"Success level": 70% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.27

20100903

Astronomy quiz question: time for next moon phase

Astronomy 210 Quiz 1, Fall Semester 2010
Cuesta College, San Luis Obispo, CA

Approximately how much time elapses between consecutive moon phases?
(A) An hour.
(B) 12 hours.
(C) 24 hours.
(D) Several days.
(E) 28 days.

Correct answer: (D)

With eight named moon phases, and approximately 28 days for a cycle of moon phases (a "moonth"), it takes one week for each quarter, or 3.5 days ("several days") to go to to next consecutive moon phase.

Section 70160
(A) : 1 student
(B) : 7 students
(C) : 12 students
(D) : 11 students
(E) : 10 students

"Success level": 31% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.55

20100902

Overheard: star naming

Astronomy 210, Fall Semester 2010
Cuesta College, San Luis Obispo, CA

(Overheard at the start of the class, as the instructor reads student comments and questions submitted for a weekly online reading assignment.)

Instructor: (Reading student question.) "'If you could name a star, what would you name it?'"

(Beat.)

Instructor: "I wouldn't name it after myself. I would name it after my wife."

Students: "Awww."

Student: "What's your wife's name?"

Instructor: "Mrs. P-dog."

Astronomy quiz question: tilt and revolution

Astronomy 210 Quiz 1, Fall Semester 2010
Cuesta College, San Luis Obispo, CA

Together, Earth's tilt and revolution cause the __________, over the course of a year, as seen by an observer in San Luis Obispo, CA.
(A) hours between sunrise and sunset to vary.
(B) celestial north pole to wander around relative to the stars.
(C) circumpolar stars to orbit the celestial north pole.
(D) stars to rise, move across the celestial sphere, and set.

Correct answer: (A)

Response (B) is caused by precession, while both responses (C) and (D) are caused by rotation.

Section 70160
(A) : 24 students
(B) : 5 students
(C) : 6 students
(D) : 5 students

"Success level": 60% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.64