20140131

Astronomy current events question: sudden appearance of "Pinnacle Rock"

Astronomy 210L, spring semester 2014
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!)
Ian O'Neill, "Mystery Rock 'Appears' in Front of Mars Rover," January 17, 2014
http://news.discovery.com/space/mystery-rock-appears-in-front-of-mars-rover-140117.htm
The Mars Exploration Rover Opportunity observed the sudden appearance of the small white rock "Pinnacle Island" that may have been moved by:
(A) one of its wheels.
(B) a recent marsquake.
(C) evaporating dry ice snow.
(D) a lightning strike.
(E) receding floodwaters.

Correct answer: (A)

Student responses
Sections 30678, 30679, 30680
(A) : 36 students
(B) : 7 students
(C) : 3 students
(D) : 5 students
(E) : 5 students

Astronomy current events question: black hole companion to star MWC 656

Astronomy 210L, spring semester 2014
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!)
Universitat de Barcelona news release, "Spanish Researchers Discover the First Black Hole Orbiting a 'Spinning' Star," January 16, 2014
http://www.ub.edu/web/ub/en/menu_eines/noticies/2014/01/015.html
Spanish scientists determined that star MWC 656 is orbited by a black hole, based on the fact that it is invisible to telescopes, and:
(A) no other surviving stars are nearby.
(B) rich in dark matter.
(C) the star MWC 656 is steadily losing mass.
(D) absorbs gamma-ray radiation.
(E) more massive than a neutron star.

Correct answer: (E)

Student responses
Sections 30678, 30679, 30680
(A) : 7 students
(B) : 8 students
(C) : 15 students
(D) : 19 students
(E) : 9 students

Astronomy current events question: brown dwarf weather patterns

Astronomy 210L, spring semester 2014
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, "Stormy Stars? NASA's Spitzer Probes Weather on Brown Dwarfs," January 7, 2014
http://www.jpl.nasa.gov/news/news.php?release=2014-005
NASA's Spitzer Space Telescope observed __________, which may be evidence of swirling storms on brown dwarfs.
(A) jet streams.
(B) lightning flashes.
(C) periodic brightness variations.
(D) a polar vortex.
(E) molten iron rain.

Correct answer: (C)

Student responses
Sections 30678, 30679, 30680
(A) : 9 students
(B) : 13 students
(C) : 18 students
(D) : 4 students
(E) : 13 students

20140128

Online reading assignment: flipped classroom, motions and cycles (SLO campus)

Astronomy 210, spring semester 2014
Cuesta College, San Luis Obispo, CA

Students have a weekly online reading assignment (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. Full credit is given for completing the online reading assignment before next week's lecture, regardless if whether their answers are correct/incorrect. Selected results/questions/comments are addressed by the instructor at the start of the following lecture.

The following questions were asked on reading textbook chapters and previewing presentations on Earth's rotation/precession/revolution/tilt, the moon's motions and cycles, and watching two video presentations on the flipped class: "What Is the Flipped Class?" and "How the Flipped Classroom Works."

Selected/edited responses are given below.

Describe something you found interesting from the assigned textbook reading or presentation preview, and explain why this was personally interesting for you.
"Something that I found interesting in the presentation preview was that a precession for Earth takes 26,000 years. I thought this was interesting because that seems like a crazy long amount of time, especially because rotation only takes 24 hours."

"Reading about how ancient astronomers could measure the sky and even discover how the sky worked, just by observing, was very interesting to me. It amazes me how well they could learn especially without the technology we have today and also amazes me how much our knowledge and observations with technology has developed since then."

"I never realized how the seasons were determined in nature! I think it is interesting that the seasons are caused by the different levels of solar energy! The energy is received from the Earth's hemispheres and those solar levels change throughout the year. I think it is interesting because here on the central coast we don't experience traditional seasons. (I think we are lucky.)"

"I found the entire segment about the zodiac constellations to be highly interesting. I've always been fascinated with astrology and it will be interesting to learn about them from a more scientific point of view."

"I liked learning about what causes the phases of the moon. Seeing the moon change shapes is so common, we often forget that there's a science behind it and a reason for the specific shapes."

"I like the flipped classroom model. I honestly get really bored during lecture sometimes and doing interactive work and group work makes class so much more enjoyable."

"I found it interesting that season's aren't caused by a change in the distance between Earth and sun, but instead the amount of solar energy the hemispheres of Earth receive."

Describe something you found confusing from the assigned textbook reading or presentation preview, and explain why this was personally confusing for you.
"The part of the presentation about the north star changing or there may eventually be no north star was confusing to me, because I didn't really understand why."

"I am still a little confused on the phases of the moon. I tried focusing on this part in the book on page 24 but I still am having trouble wrapping my mind around how to remember the different phases."

"It confuses me how the rotation axis can precess around a full circle in 26,000 years, but Earth takes 24 hours to complete a rotation."

"I need some help visualizing ecliptic movement and I don't understand the phases of the moon at all."

"I still do not fully understand how to categorize a moon phase, more than anything the definition of first and third quarter."

"I am a bit confused on the differences between a crescent moon and one that is gibbous."

"I did not really understand the zodiac signs. I wasn't able to visualize in the way that I could visualize the other concepts in the section. The change in months and the different alignments of the constellations was just a little more overwhelming than it was clear."

What date would Virgo be just above the east horizon, as seen by an observer at 11 PM in San Luis Obispo, CA? (Ignore daylight saving time.)
February 20.  ***************************** [29]
April 25.  * [1]
July 4.  * [1]
August 20.  ** [2]
(Unsure/guessing/lost/help!)  ******* [7]

Match these cycles with their approximate duration.
(Only correct responses shown.)
Earth's rotation: 24 hours [95%]
Earth's revolution: one year [91%]
Earth's precession: 26,000 years [100%]
The moon's revolution: one month [85%]

Place these moon phases in chronological order in their cycle (starting with new moon).
(Only correct responses shown, in unscrambled order.)
New moon: first [100%]
Waxing crescent: second [83%]
First quarter: third [86%]
Waxing gibbous: fourth [79%]
Full moon: fifth [91%]
Waning gibbous: sixth [76%]
Third quarter: seventh [81%]
Waning crescent: eighth [76%]

Explain what is different about homework in a flipped class.
"The homework in a flipped classroom is different because instead of going over something I was taught in the previous lecture, I now have to read it myself and see what I do and what I don't understand."

"The homework is online and is more engaging for the student. It doesn't stress the student out as much. They don't have to try to remember to bring the assignment to class."

"Assigned homework is usually what the teacher in a 'regular' class would be lecturing about, so that class time can be spent applying knowledge."

Describe where/when most student learning occurs in a flipped class.
"Most of the learning is done in class by applying the concepts and practicing to help learn."

"The most student learning comes from supervised in class projects and team discussions. Also, in class once we have done the required reading we are able to ask any and all questions that we need clarified, therefore saving time and energy while learning the maximum amount."

"Anytime! since I can access videos using a computer or mobile device, I can learn anywhere and anytime!"

"I would say it depends on the students' learning style. For the students who learn by doing, well they probably learn more in class by doing the activities.

"In my opinion with a flipped class the student is always learning just in a different way. At home they are able to learn at their speed, reviewing all the future class slides and notes. Then answer some questions and ask some questions. In class the student is learning with a hands on approach doing more class exercises and the student already has some idea of what is going to be covered in the class. So you are not just dropped into the deep end of learning."

Ask the instructor an anonymous question, or make a comment. Selected questions/comments may be discussed in class.
"I find it interesting just how much physics and math seem to naturally fit with astronomy. I am a math kind of person but not necessarily a science person, however I am looking forward to seeing how entwined these two subject really are in the form of astronomy."

"The star chart was rather confusing, although you did teach us about it, I still found some difficulties with it. It's mainly because it is a new tool that I've never used before. I believe with more practice, I will be able to master it."

"How long have you been teaching with the flipped class model?" (This is my second semester of a completely flipped classroom teaching for this astronomy class.)

"I thought the flipped classroom concept was very interesting. I've never truly liked the standard lecture-based methods college professors tend to use, but also am not the greatest fan of an overload of homework either. I'm excited to see how this program, which seems to be a happy medium, helps me succeed in this course." (I'm excited, too.)

"I was nervous about taking a boring science class that I might fall asleep in after the first two hours, but after attending the first class session I am really looking forward to the flipped class environment and I think this will be my most looked forward to and interesting class."

"Do we need to buy a 'clicker' from the bookstore?" (No. No clickers, no Scantrons®.)

"What is the best textbook to buy instead of buying the newest addition of ASTRO2? Is an old edition acceptable, or has too much information changed?" (About 90% of the information is the same. The first edition of ASTRO has very different chapter numbers, so you would need to borrow a friend's copy of ASTRO2 to figure out how they've been renumbered.)

Online reading assignment: total internal reflection

Physics 205B, spring semester 2014
Cuesta College, San Luis Obispo, CA

Students have a weekly online reading assignment (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. Full credit is given for completing the online reading assignment before next week's lecture, regardless if whether their answers are correct/incorrect. Selected results/questions/comments are addressed by the instructor at the start of the following lecture.

The following questions were asked on reading textbook chapters and previewing presentations on total internal reflection.

Selected/edited responses are given below.

Describe what you understand from the assigned textbook reading or presentation preview. Your description (2-3 sentences) should specifically demonstrate your level of understanding.
"If light is going from a medium with a higher index of refraction (lower speed) into a medium with a lower index of refraction (higher speed) then there is a possibility of total internal reflection if the incident angle is equal to or greater than the critical angle. If the incident angle is less than the critical angle Snell's law can be used to determine the transmission angle."

"I would say, especially in equation form, I am the most comfortable with Snell's Law. I would also say that I have a fairly decent grasp on the critical angle for light traveling between two media."

"I understand that diamonds sparkle because of the light reflecting internally many times before transmitting. And that fiber optics follow a similar principle in order to maximize the distance the light will travel."

"I understand when Snell's law does and doesn't apply in regard to comparing the incident angle and the critical angle."

"The critical angle equation is just an equation manipulation of Snell's law. I also get that for TIR light moves from a high to lower medium index of refraction."

Describe what you found confusing from the assigned textbook reading or presentation preview. Your description (2-3 sentences) should specifically identify the concept(s) that you do not understand.
"Equations, equations, equations. For me, once I figure out where everything goes, and why it goes there, I should be fine."

"I'm having some trouble determining which type of reflection is applied in certain situations (i.e. specular vs. diffuse vs. TIR)."

"I'm confused on distinguishing total internal reflection and no transmission. I'm not sure if they are separate or if they are the same thing."

"I thought I understood critical angles, but now I'm not sure."

If the incident angle of a light ray is less than the critical angle, the light ray will be:
reflected.  ** [2]
transmitted.  ******** [8]
(Both of the above choices.)  ************************ [24]
(Neither of the above choices.)  [0]
(Unsure/guessing/lost/help!)  * [1]

If the incident angle of a light ray is equal to the critical angle, the light ray will be:
reflected.  ********** [10]
transmitted.  **** [4]
(Both of the above choices.)  *************** [15]
(Neither of the above choices.)  *** [3]
(Unsure/guessing/lost/help!)  *** [3]

If the incident angle of a light ray is greater than the critical angle, the light ray will be:
reflected.  **************************** [28]
transmitted.  ** [2]
(Both of the above choices.)  * [1]
(Neither of the above choices.)  *** [3]
(Unsure/guessing/lost/help!)  * [1]

Total internal reflection is possible when a light ray in a __________ medium hits a boundary with a __________ medium.
faster; slower.  ********* [9]
slower; faster.  ********************* [21]
(Both of the above choices.)  ** [2]
(Unsure/guessing/lost/help!)  *** [3]

When a rainbow is created, the "reflections" that occur in a raindrop are __________ reflections.
specular.  *********** [11]
diffuse  ******** [9]
total internal.  ********* [9]
(Unsure/guessing/lost/help!)  ****** [6]

Ask the instructor an anonymous question, or make a comment. Selected questions/comments may be discussed in class.
"How you can really determine if a diamond is real or fake? I don't understand what the determining factors look like in real life and how easy to recognize they are." (I will bring an obviously fake diamond to class, along with an unknown real/fake diamond for you to compare with.)

"I need some help finding when to apply Snell's law." (If Snell's law can give you a numerical answer, then you are allowed to use it. If it can't give you a numerical answer, then you can't use it.)

"I like spending about half of lecture doing problems so we could get your direct help to clarify anything."

"Could you go through some of the examples from the blog? I'm having trouble with the applications of total internal reflection."

"I liked how the surveys were worded last semester with the questions asking what we found interesting and what we found confusing (as opposed to what we understand or don't understand)."

"Is this box optional?" (If you completed and commented on all the above questions, yes. If you did not, then you should put something substantive here.)

20140127

Online reading assignment: flipped classroom, motions and cycles (NC campus)

Astronomy 210, spring semester 2014
Cuesta College, San Luis Obispo, CA

Students have a weekly online reading assignment (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. Full credit is given for completing the online reading assignment before next week's lecture, regardless if whether their answers are correct/incorrect. Selected results/questions/comments are addressed by the instructor at the start of the following lecture.

The following questions were asked on reading textbook chapters and previewing presentations on Earth's rotation/precession/revolution/tilt, the moon's motions and cycles, and watching two video presentations on the flipped class: "What Is the Flipped Class?" and "How the Flipped Classroom Works."

Selected/edited responses are given below.

Describe something you found interesting from the assigned textbook reading or presentation preview, and explain why this was personally interesting for you.
"I personally found the zodiac part of the presentation to be interesting. I have yet to get to the textbook reading but if it discusses the zodiac signs further I would be very interested. Zodiac signs are just appealing to me and seem to have some partial truths at times with the people I've met which is why I enjoy it."

"I found the cycle of the seasons very interesting because it caused me to think about the other places in the world, and how they are in different sides of the equator and have different views of the sky and have different amounts of light and warm and cold."

"The fact that the north star wasn't the same as 4,800 years ago, and it will change steadily due to precession."

"I had not known the names for the moon's phases and I found it interesting to discover that there is much more to it than I had previously thought."

"The cycle of the seasons due to tilt and revolution was pretty interesting. Once you read about it and are able to visualize it, it's fairly straightforward. In any case, it's still exciting to be able to articulate it."

Describe something you found confusing from the assigned textbook reading or presentation preview, and explain why this was personally confusing for you.
"There has not been anything confusing yet."

"I didn't get a clear understand of why solstices and equinoxes occur."
"I was confused how you can tell if the moon is waxing or waning from a picture. I thought more information would be necessary."

"I found most of the reading confusing mostly because I do not learn well from reading. Concepts do not typically stick in my head unless I have someone explaining them to me."

"I still do not fully understand how to categorize a moon phase, more than anything the definition of first and third quarter."

"I am a bit confused on the differences between a crescent moon and one that is gibbous."

"I did not really understand the zodiac signs. I wasn't able to visualize in the way that I could visualize the other concepts in the section. The change in months and the different alignments of the constellations was just a little more overwhelming than it was clear."

What date would Virgo be just above the east horizon, as seen by an observer at 11 PM in San Luis Obispo, CA? (Ignore daylight saving time.)
February 20.  ***************** [17]
April 25.  [0]
July 4.  * [1]
August 20.  * [1]
(Unsure/guessing/lost/help!)  **** [4]

Match these cycles with their approximate duration.
(Only correct responses shown.)
Earth's rotation: 24 hours [96%]
Earth's revolution: one year [83%]
Earth's precession: 26,000 years [92%]
The moon's revolution: one month [75%]

Place these moon phases in chronological order in their cycle (starting with new moon).
(Only correct responses shown, in unscrambled order.)
New moon: first [92%]
Waxing crescent: second [83%]
First quarter: third [87%]
Waxing gibbous: fourth [79%]
Full moon: fifth [88%]
Waning gibbous: sixth [75%]
Third quarter: seventh [79%]
Waning crescent: eighth [67%]

Explain what is different about homework in a flipped class.
"In a flipped class, lectures are reviewed at home on the students time and homework is done in class."

"You learn the material before class, and if something seemed confusing questions will be answered in class the following day."

"This is pretty similar to what I've experienced in other classes so I'm not new to it."

Describe where/when most student learning occurs in a flipped class.
"I think most student learning would take place in class when the student has the chance to solidify his/her understanding of the lecture and pose any questions to the instructor."

"A majority of the learning will be done at home however the understanding process will be done in class."

"Depends on the student. Some learn by listening to the lecture. Some learn by asking questions. Some learn by doing hands-on activities. Some learn by reading and taking notes. And with a flipped class everyone has the opportunity to learn the way they learn."

Ask the instructor an anonymous question, or make a comment. Selected questions/comments may be discussed in class.
"I've never taken a physics class--will this make astronomy more difficult for me compared to a person who has taken a physics class?" (No. This should not be a problem. Trust me.)

"How important is it to read the textbook if you read and understand the presentation previews." (It depends on the subject; right now it's more important to understand the visual information in the presentations than read about them in the textbook. Other subjects require more textbook reading, while the presentations are just brief outlines.)

"This is the first 'flipped' class I have been in and I am curious about how much of the pre-class-at-home-lecture we will be discussing in class. Is the amount predetermined, or will the amount based on the class' overall level of understanding of the topics?" (Little of both. Whatever you need. I'm flexible.)

"What are your beliefs about astrology predicting the future?" (Harmless fun. Your opinion may differ. Though I can't test you on your beliefs about astrology, whatever they are, I will certainly teach you, and test you on your understanding of the historical basis behind "sun-sign" astrology.)

Online reading assignment: reflection and refraction

Physics 205B, spring semester 2014
Cuesta College, San Luis Obispo, CA

Students have a weekly online reading assignment (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. Full credit is given for completing the online reading assignment before next week's lecture, regardless if whether their answers are correct/incorrect. Selected results/questions/comments are addressed by the instructor at the start of the following lecture.

The following questions were asked on reading textbook chapters and previewing a presentation on redirecting light (reflection and refraction).

Selected/edited responses are given below.

Describe what you understand from the assigned textbook reading or presentation preview. Your description (2-3 sentences) should specifically demonstrate your level of understanding.
"I understand that from one medium to another, electromagnetic waves will have the same frequency but the speed will change proportionally with the wavelength. I also understand the diagram regarding the changes in angles in to Snell's law."

"Although I already knew this from the spectroscopy in biology, I always find it interesting that visible light is only what we see but is included in the entire electromagnetic spectrum."

Describe what you found confusing from the assigned textbook reading or presentation preview. Your description (2-3 sentences) should specifically identify the concept(s) that you do not understand.
"I was confused on how to use the equation for light traveling through two different media."

"Can we please discuss Snell's Law in more detail in class? I want to understand what the practical applications are, and understand how to use and apply it."

"Although I'm not confused now, I know I will be as soon as I try to use the equations. The parameters for light I know I will mix up which are independent and which are dependent. Snell's law also confuses me a bit."

A ray of light travels through air (nair = 1.0), or through glass (nglass = 1.5). Light travels slower in:
Air.  *** [3]
Glass.  ********************************* [33]
(There is a tie.)  * [1]
(Unsure/guessing/lost/help!)  * [1]

A diagonal ray of light in air (nair = 1.0) is transmitted down into glass (nglass = 1.5). Explain using Snell's law why the incident angle in air (θi) is greater than the transmitted angle in glass (θt).
"I would say that the angle is smaller due to the very nature of Snell's Law. Since nglass is larger, the angle must be smaller so that nglass·sinθglass = nair·sinθair."

"I'm struggling with Snell's law."

What is your preference for denoting the inverse sine operation?
Arcsin.  ****** [6]
Sin-1.  **************************** [28]
(No preference.)  *** [3]
(Unsure/guessing/lost/help!)  * [1]

Ask the instructor an anonymous question, or make a comment. Selected questions/comments may be discussed in class.
"After going over the online presentation, reading the textbook, and taking notes I feel that I understand the concepts but need to be shown how to apply the concepts to problems. Can we do some of that in class?" (Yes.)

"It's good to be back to another semester of the physical universe!" (But you never actually left the physical universe.)

"Could you explain in your words how the mirage phenomenon works?" (Wait until we discuss total internal reflection.)

"I was confused as to what makes some of the light on the electromagnetic spectrum not visible to the eye. What makes light visible to the eye?" (Crudely speaking, antennae of a given size are sensitive to light waves that have approximately the same wavelength. Large antennae transmit and receive long wavelength radio waves. Cellphones contain small antennae for shorter wavelength radio waves. For visible light, its very small wavelengths correspond to the electron bonds in certain proteins in your rod and cone cells. Receiving visible light causes these electron "antennae" to absorb energy which changes the structure of these proteins, and your rod and cone cells perceive the presence of these transformed proteins as "seeing" light.)

20140126

SPCI pre-test comparison: Cuesta College SLO vs. NC campuses

The Star Properties Concept Inventory (SPCI, developed by Janelle Bailey, University of Nevada-Las Vegas) was administered to Astronomy 210 (one-semester introductory astronomy) students at Cuesta College, San Luis Obispo, CA during the first week, at both the main San Luis Obispo campus and the North County campus at Paso Robles.

NC campus
(section 30674)    
SLO Campus
(section 30676)
N31 students*50 students*
low  3  0
mean      6.4 ± 2.0  6.5 ± 3.2
high1116

*Excludes students with negative informed consent forms (*.pdf)

Student's t-test of the null hypothesis results in p = 0.88 (t = -0.416, sdev = 2.78, degrees of freedom = 79), thus there is no significant difference between the pre-test scores of these two sections.

Later this semester (spring semester 2014), a comparison will be made between the pre- to post-test gains for both sections, separate and combined.

Previous posts:
  • SASS, SPCI and student learning outcomes assessment (fall semester 2013) .
  • SASS, SPCI and student learning outcomes assessment (spring semester 2012).
  • SPCI and student learning outcomes (fall semester 2011).
  • SPCI gains (spring semester 2009).
  • SPCI gains (spring semester 2008).
  • SPCI gains (fall semester 2007).
  • SPCI gains (summer session 2007).
  • SPCI gains (spring semester 2006-spring semester 2007).
  • 20140125

    Flashcard question: texting/social networking in class (spring semester 2014)

    Astronomy 210, spring semester 2014
    Cuesta College, San Luis Obispo, CA

    "I Forgot My Phone"
    Charlene deGuzman and Miles Crawford
    http://youtu.be/OINa46HeWg8

    After showing a short movie depicting the pervasiveness of smartphone use at the start of the semester, students in introductory astronomy students at Cuesta College were asked a subjective question regarding their attitudes towards texting and social networking smartphone use in class. This is part of a think-pair-share activity using flashcards to answer syllabus quiz questions.

    Texting/social networking is acceptable behavior in class.
    (A) Strongly disagree.
    (B) Disagree.
    (C) Neutral.
    (D) Agree.
    (E) Strongly agree.

    Student responses (pre-discussion)
    Astronomy 210
    Section 30674 (SLO campus)
    (A) : 1 student
    (B) : 3 students
    (C) : 29 students
    (D) : 3 students
    (E) : 0 students

    Astronomy 210
    Section 30676 (NC campus)
    (A) : 0 students
    (B) : 8 students
    (C) : 13 students
    (D) : 4 students
    (E) : 0 students

    Students were then asked to share their answers and discuss with each other the reasoning behind their choices, and to vote again.

    Student responses (post-discussion)
    Astronomy 210
    Section 30674 (SLO campus)
    (A) : 3 students
    (B) : 3 students
    (C) : 32 students
    (D) : 3 students
    (E) : 0 students

    Astronomy 210
    Section 30676 (NC campus)
    (A) : 0 students
    (B) : 8 students
    (C) : 15 students
    (D) : 4 students
    (E) : 0 students

    Students were asked to share their responses during the following whole-class discussion. Most responses were along the lines of texting/social networking being "distracting," "inappropriate," and "disrespectful," but some students remarked that emergency contact purposes (or similar circumstances) or looking up information pertinent to lecture might be considered acceptable uses of smartphones. While indiscriminate use of smartphones during instruction would be detrimental to learning, the social norm seems to be that they would be tolerated as long as smartphone use was not disruptive to other students.

    These responses and student opinions were then used to set the policy, via consensus, regarding texting and social networking during class time.

    Previous posts:
  • Flashcard question: texting/social networking in class (fall semester 2013).
  • Flashcard question: texting/social networking in class (fall semester 2011).
  • Astronomy in-class activity: astronomy in the marketplace tags

    Astronomy 210 In-class activity 1, spring semester 2014
    Cuesta College, San Luis Obispo, CA

    140125-cars
    http://www.flickr.com/photos/waiferx/12141482294/
    Originally uploaded by Waifer X

    Wordle.net tag cloud for astronomy-related car brand names, generated by responses from Astronomy 210 students at Cuesta College, San Luis Obispo, CA ( http://www.wordle.net/show/wrdl/7488709/Untitled ).


    140125-food-1
    http://www.flickr.com/photos/waiferx/12141482504/
    Originally uploaded by Waifer X

    Wordle.net tag cloud for astronomy-related food brand names available in a supermarket, generated by responses from Astronomy 210 students at Cuesta College, San Luis Obispo, CA (http://www.wordle.net/show/wrdl/7488717/Untitled ).


    140125-nonfood-1
    http://www.flickr.com/photos/waiferx/12141329353/
    Originally uploaded by Waifer X

    Wordle.net tag cloud for astronomy-related non-food brand names available in a supermarket, generated by responses from Astronomy 210 students at Cuesta College, San Luis Obispo, CA (http://www.wordle.net/show/wrdl/7488719/Untitled).


    Students find their assigned groups of three to four students, and work cooperatively on an in-class activity worksheet to discuss car brand names, and food and non-food brand names found in supermarkets (adapted from D. Schatz, "Why Should We Care About Exploding Stars?" Universe in the Classroom, no. 8, Spring 1987 (http://www.astrosociety.org/education/publications/tnl/08/stars2.html).

    There are many astronomy-related brand names. Consider car brand names (old and new); and brand names for food and non-food items that are typically found in the supermarket. Do not consider titles of TV shows, movies, or books.

    List at least five astronomy-related car brand names.

    Student responses
    Sections 30674, 30676
    Taurus, Aero, Astro, Eclipse, Mercury, Warstar
    Saturn, Subaru, Galaxy, Mercury, RangeRover
    Astro, Galaxy, Taurus
    Saturn, Eclipse, Mercury
    Saturn, Mercury, Charger
    Mercury, Taurus, Saturn
    Nova, Comet, Galaxy, Taurus, Geo
    Saturn, Mercury, Comet, Sunfire, Astro
    Saturn, Mercury, Subaru, Galaxy
    Saturn, Mercury, Eclipse, Stargazer
    Astro, Saturn, Mercury, Comet, Eclipse
    Saturn, Mercury, Sunfire, Taurus
    Astro, Mercury, Saturn, Galaxy, Voyager
    Saturn, Mercury, Galaxy, Astro
    Nova, Astro, Ram, Saturn, Mercury
    Saturn, Infiniti, Mercury, Nova, Galaxy
    Galaxy, Saturn, Subaru, LandRover, Aerostar, Infiniti
    Mercury, Saturn, Astro, Eclipse, Infiniti
    Mercury, Eclipse, Saturn, Taurus, Nova
    Saturn, Eclipse, Taurus, Galaxy, Navigator
    Saturn, Mercury, Mazda, Explorer, Navigator
    Saturn, Mercury, Nova, Infiniti, Solara
    Saturn, Mercury, Eclipse
    Saturn, Mercury, Astro, Eclipse, Infiniti
    Galaxy, Navigator, Saturn, Taurus
    Saturn, Astro, Mercury, Galaxy, Eclipse

    List at least five astronomy-related food brand names typically found in the supermarket.

    Student responses
    Sections 30674, 30676
    MoonPies, AstroPops, Starburst, Orbit, MarsBars, ChickenandStars, sunflowerseeds, Corona
    Orbit, Starbucks, Starburst, MilkyWay, MoonPies
    Rocketcheesecracker, StarCrunch, MilkyWay, MarsBars, Astronautfood, AstroPops, starfruit, SunnyD, Sunkist, Moonpies
    MoonPies, StarCrunch, Starburst, AstroPops, MilkyWay, MarsBars
    LunaBars, MilkyWay, Starburst
    MilkyWay, MarsBars, MoonPies, starfruit, Starburst
    MoonPie, SunChips, Starburst, MilkyWay, MarBars, Orbit, SunnyD, SunMaid, Sunkist, StarKisttuna
    LuckyCharms, Starbucks, MoonPies, MilkyWay
    MilkyWay, Orbit, MoonPies, Starburst, Starbucks
    MilkyWay, MoonPies, Starburst, AstroPuffs, Orbit, Eclipse, MarsBars
    MilkyWay, sunflowerseeds, SunChips, Starbucks, Starburst, SunnyD
    LunaBars, Cosmicbrownies, SunnyD, CapriSun
    BlueMoon, Moonshine, LunaBars, Skyyvodka, MilkyWay
    BlueMoon, MoonPies, Sunkist, Starburst, MarsBars
    Starburst, MilkyWay, MarsBars, Sunkist, LunaBars
    MarsBars, MilkyWay, Tang, Starburst, Sunkist, SunnyD
    Rockstar, MilkyWay, Starburst, MarsBars, Orbit
    MilkyWay, Sunkist, Starfruit, Starburst, CapriSun, SunChips, SunnyD
    Starburst, StarKisttuna, MarsBars, Sunkist, SunDrop, MilkyWay
    MilkyWay, MarsBars, SunnyD, MoonPies
    Starburst, BlueMoon, Sunkist, MilkyWay, SunChips
    MoonPies, MilkyWay, Orbit, Starburst, Mooncake
    LunaBars, SunChips, StarFarms, MilkyWay, Starburst
    MoonPies, AstroPops, SunnyD, Starburst, MilkyWay
    Starburst, MilkyWay, Orbit, Starbucks, MoonPies
    Starburst, MilkyWay, MarsBars, Sunkist, SunnyD

    List at least five astronomy-related non-food brand names typically found in the supermarket.

    Student responses
    Sections 30674, 30676
    Tide, Cosmomagazine, Starmagazine, moonflowers, morningglories
    Crest, Scope
    Constellationwinery, ColgateGalaxy, sunscreen, spacethemepartydecorations
    FiveStarnotebooks
    BlueMoon, Rockstar, Orbit, SamsungGalaxy, Comet
    BlueMoon, MillerLite
    Comet, Geo, Sun, SiriusXM
    BlueMoon, babymobile, SamsungGalaxy, calendars
    Crest, BlueMoon, CoorsLight, BudLight
    BlueMoon, sunflowers, Cosmomagazine, venusflytrap, Venusrazors
    BlueMoon, Moonshine, Skyyvodka
    Astroglide, Comet, FiveStarnotebooks, ZiplocSpaceBags
    Comet, Sunburst, BlueMoon
    Comet, Venusrazors, Starmagazine, Rockstar, FiveStarnotebooks
    Comet, Cosmomagazine, ConstantCommenttea, Venusrazors, Starmagazine, FiveStarnotebooks
    BlueMoon, Moonshine, Comet, Tide, sunscreen
    BlueMoon, UVBlue, Skyyvodka, Moonshine, Comet
    Venusrazors, Comet, Orbit
    Venusrazors, Comet, Orbit
    BlueMoon, Comet, BuzzLightyear, Moonshine, SamsungGalaxy
    Venusrazors, BlueMoon, Skyyvodka, MoonShoes
    MoonShoes, BlueMoon, Skyyvodka, Venusrazors
    Comet, Venusrazors
    Cosmomagazine, BlueMoon, Comet, Skyyvodka, Venusrazors

    Previous posts:

    20140111

    Physics final exam question: normal force on truck going over hill

    Physics 205A Final Exam, fall semester 2013
    Cuesta College, San Luis Obispo, CA

    Cf. Giambattista/Richardson/Richardson, Physics, 2/e, Problems 5.39, 5.41

    A truck drives over the top of a hill that has a circular radius, without losing contact with the hill. This 
truck then drives over the top of the same hill with a slightly faster speed, but it is still in contact with the hill. Discuss 
why the magnitude of the upwards normal force of the hill on the truck is smaller when the truck is going faster over the hill. Explain your reasoning by using free-body diagram(s), the properties of forces and Newton's laws.

    Solution and grading rubric:
    • p:
      Correct. Understands that the truck has two vertical forces acting on it:
      Weight force of Earth on truck (downwards, magnitude w = m·g).
      Normal force of road on truck (upwards, magnitude varies but must be less than w).
      For either driving fast or slow over the hill, because the truck is (momentarily) undergoing uniform circular motion as it drives over the top of the hill, then Newton's second law applies to the motion of the truck (speed is constant but direction of the velocity vector is changing), and the net force must point downwards (towards the center of the circular hill). This means that the upwards normal force must have a magnitude less than the magnitude of the weight force. Then compares driving fast over the top of the hill versus driving slow over the top of the hill:
      • the net force on the truck has a magnitude given by m·v2/r that is greater for the case of driving faster over the hill, and has a smaller magnitude for driving slower over the hill (as m and r are the same for either case);
      • the downwards weight force on the truck is constant, as it does not depend on how fast or slow the truck drives at the top of the hill;
      • the upwards normal force must be smaller for the faster speed case, in order to result in a greater downwards net force.
    • r:
      As (p), but argument indirectly, weakly, or only by definition supports the statement to be proven, or has minor inconsistencies or loopholes.
    • t:
      Nearly correct, but argument has conceptual errors, or is incomplete.
    • v:
      Limited relevant discussion of supporting evidence of at least some merit, but in an inconsistent or unclear manner. Some attempt at analyzing forces, free-body diagrams, and Newton's laws.
    • x:
      Implementation/application of ideas, but credit given for effort rather than merit. Approach does not substantively utilize forces, free-body diagrams, and Newton's laws.
    • y:
      Irrelevant discussion/effectively blank.
    • z:
      Blank.
    Grading distribution:
    Sections 70854, 70855, 73320
    Exam code: finaln0M3
    p: 2 students
    r: 0 students
    t: 16 students
    v: 16 students
    x: 24 students
    y: 2 students
    z: 1 student

    A sample "p" response (from student 0618):

    A sample "x" response (from student 0419):

    Another sample "x" response (from student 1969):

    And another sample "x" response (from student 1994):

    Yet another sample "x" response (from student 2999):

    And one more sample "x" response (from student 7667):

    Physics final exam question: climber rappelling down cliff edge

    Physics 205A Final Exam, fall semester 2013
    Cuesta College, San Luis Obispo, CA

    Cf. Giambattista/Richardson/Richardson, Physics, 2/e, Problem 8.19

    "Transportation Soldiers conduct rappel tower training"
    Virginia Guard Public Affairs
    flic.kr/p/cQRGch

    A climber is approximated as a uniform beam, with a pivot point at the feet, and a rope attached to the center. The climber is about to rappel back down from a cliff edge, leaning back with the rope initially horizontal. A little later, the climber is lower, leaning back with the same angle, but the rope is no longer horizontal. Discuss why there is less tension in the rope for the latter case. (Ignore stretching in the rope.) Explain your reasoning using diagram(s) with locations of forces and lever arms, the properties of torques, and Newton's laws.

    Solution and grading rubric:
    • p:
      Correct. Understands that (1) the counterclockwise torque due to weight is the same in either case, such that from the static equilibrium condition (Newton's first law for rotations), the clockwise torque due to the rope's tension force must be the same in either case, and (2) the larger lever arm r for the second case will mean a smaller tension force.
    • r:
      As (p), but argument indirectly, weakly, or only by definition supports the statement to be proven, or has minor inconsistencies or loopholes. Does not explicitly explain in (1) why the clockwise torques due to the rope tension forces are the same.
    • t:
      Nearly correct, but argument has conceptual errors, or is incomplete. Discusses that r would be larger for the second case, but does not explicitly explain this on a diagram and/or with trigonometry.
    • v:
      Limited relevant discussion of supporting evidence of at least some merit, but in an inconsistent or unclear manner. Some attempt at manipulating the relationship between torque, force, and lever arm.
    • x:
      Implementation/application of ideas, but credit given for effort rather than merit. Approach does not substantively use relationship between torque, force, and lever arm.
    • y:
      Irrelevant discussion/effectively blank.
    • z:
      Blank.
    Grading distribution:
    Sections 70854, 70855, 73320
    Exam code: finaln0M3
    p: 6 students
    r: 14 students
    t: 19 students
    v: 17 students
    x: 2 students
    y: 1 student
    z: 2 students

    A sample "p" response (from student 2419):

    Physics final exam question: speed of waves along standing wave strings

    Physics 205A Final Exam, fall semester 2013
    Cuesta College, San Luis Obispo, CA

    Cf. Giambattista/Richardson/Richardson, Physics, 2/e, Conceptual Questions 11.3, 11.4, Multiple-Choice Questions 11.5, 11.6, 11.8

    A string has its tension set by a hanging mass, and resonates at its fundamental frequency. If a shorter length of the string is used (changing its fundamental frequency), discuss why the speed of waves along this string does not change. (Ignore stretching in the string.) Explain your reasoning using the properties of wave speeds, periodic waves, and standing waves.

    Solution and grading rubric:
    • p:
      Correct. Understands that (1) wave speed depends on tension and linear mass density, and (2) since neither of these are changed by using a shorter portion of this same string (with the same mass hanging from it), then the wave speed remains constant.
    • r:
      As (p), but argument indirectly, weakly, or only by definition supports the statement to be proven, or has minor inconsistencies or loopholes.
    • t:
      Nearly correct, but argument has conceptual errors, or is incomplete.
    • v:
      Limited relevant discussion of supporting evidence of at least some merit, but in an inconsistent or unclear manner. At least understands the relationship between wave parameters.
    • x:
      Implementation/application of ideas, but credit given for effort rather than merit.
    • y:
      Irrelevant discussion/effectively blank.
    • z:
      Blank.
    Grading distribution:
    Sections 70854, 70855, 73320
    Exam code: finaln0M3
    p: 17 students
    r: 25 students
    t: 7 students
    v: 9 students
    x: 3 students
    y: 0 students
    z: 0 students

    A sample "p" response (from student 7810):

    Physics final exam question: heat conducted through different-orientation bricks

    Physics 205A Final Exam, fall semester 2013
    Cuesta College, San Luis Obispo, CA

    Cf. Giambattista/Richardson/Richardson, Physics, 2/e, Example 14.10, Practice Problem 14.10, Problem 14.57

    A brick can be placed in either of two orientations. The bottom of each brick is immersed in 20° C water, while the top of each brick is heated to 80° C. (Ignore the very slight thermal expansion of these bricks.) Discuss why these two bricks will not conduct the same amount of heat per time. Explain your answer using the properties of heat, temperature, and heat transfer.

    Solution and grading rubric:
    • p:
      Correct. Heat is conducted from the top to the bottom of each brick, at a rate (1) proportional to the cross-sectional area, and (2) inversely proportional to the length (in this case, height), such that the wider, shorter brick will conduct heat at a rate faster than the narrower, taller brick.
    • r:
      As (p), but argument indirectly, weakly, or only by definition supports the statement to be proven, or has minor inconsistencies or loopholes. Typically argues only (1) area, or only (2) length as a factor in why the wider, shorter brick will conduct heat faster than the narrower, taller brick.
    • t:
      Nearly correct, but argument has conceptual errors, or is incomplete.
    • v:
      Limited relevant discussion of supporting evidence of at least some merit, but in an inconsistent or unclear manner. At least recognizes different factors (1)-(2) and attempts to discuss heat conduction along the length of the bars.
    • x:
      Implementation/application of ideas, but credit given for effort rather than merit. Discussion based on phenomena other than heat conduction along the length of the bricks.
    • y:
      Irrelevant discussion/effectively blank.
    • z:
      Blank.
    Grading distribution:
    Sections 70854, 70855, 73320
    Exam code: finaln0M3
    p: 24 students
    r: 31 students
    t: 1 student
    v: 3 students
    x: 0 students
    y: 1 student
    z: 1 student

    A sample "p" response (from student 0494):

    Another sample "p" response (from student 2395):

    A sample "r" response (from student 0825), discussing only how the cross-sectional area A affects the flow of heat conducted through the bricks:

    A sample "r" response (from student 1025), discussing only how the length (height) d affects the flow of heat conducted through the bricks:

    Physics final exam problem: frictionless box pushing box with sliding friction

    Physics 205A Final Exam, fall semester 2013
    Cuesta College, San Luis Obispo, CA

    Cf. Giambattista/Richardson/Richardson, Physics, 2/e, Problem 4.63

    A 7.0 kg box and a 3.0 kg box are in contact with each other on a horizontal floor. The 7.0 kg box slides without friction on the floor, but the 3.0 kg box has a kinetic friction coefficient of 0.15 with the floor. A horizontal force of 5.0 N is applied to the 7.0 kg box such that both boxes are sliding together to the right. Determine the magnitude of the acceleration of these boxes. Show your work and explain your reasoning.

    Solution and grading rubric:
    • p:
      Correct. Draws free-body diagrams, and applies properties of forces and Newton's laws to determine the kinetic friction force on the 3.0 kg box, finds the net horizontal force on the system of both boxes, and implements Newton's second law to find the acceleration of both boxes.
    • r:
      Nearly correct, but includes minor math errors. One of the two points (1)-(2) correct, other is problematic/incomplete.
    • t:
      Nearly correct, but approach has conceptual errors, and/or major/compounded math errors.
    • v:
      Implementation of right ideas, but in an inconsistent, incomplete, or unorganized manner. At least some attempt at applying properties of forces and Newton's laws.
    • x:
      Implementation of ideas, but credit given for effort rather than merit. Approach does not substantively use properties of forces and Newton's laws.
    • y:
      Irrelevant discussion/effectively blank.
    • z:
      Blank.
    Grading distribution:
    Sections 70854, 70855, 73320
    Exam code: finaln0M3
    p: 13 students
    r: 4 students
    t: 7 students
    v: 17 students
    x: 13 students
    y: 2 students
    z: 5 students

    A sample "p" response (from student 0000):

    Physics final exam problem: kinetic energy loss of completely inelastic collision

    Physics 205A Final Exam, fall semester 2013
    Cuesta College, San Luis Obispo, CA

    Cf. Giambattista/Richardson/Richardson, Physics, 2/e, Problem 7.43, Comprehensive Problem 7.71

    A 0.20 kg cart launched off of a spring in the +x direction with a velocity of +0.11 m/s collides with a heavier 1.00 kg cart that is initially at rest. The carts stick together after the collision. Neglect drag and friction. Demonstrate numerically that kinetic energy is not conserved for this collision. Show your work and explain your reasoning using properties of collisions, energy (non-)conservation, and momentum conservation.


    Solution and grading rubric:
    • p:
      Correct. Applies (1) conservation of momentum to determine final velocity of the stuck-together cards, and (2) demonstrates numerically that kinetic energy is not conserved.
    • r:
      Nearly correct, but includes minor math errors. One of the two points (1)-(2) correct, other is problematic/incomplete.
    • t:
      Nearly correct, but approach has conceptual errors, and/or major/compounded math errors. Both points (1)-(2) problematic/incomplete, or one point correct while other is missing.
    • v:
      Implementation of right ideas, but in an inconsistent, incomplete, or unorganized manner. Some attempt at applying some conservation law.
    • x:
      Implementation of ideas, but credit given for effort rather than merit. No clear attempt at applying conservation laws.
    • y:
      Irrelevant discussion/effectively blank.
    • z:
      Blank.
    Grading distribution:
    Sections 70854, 70855, 73320
    Exam code: finaln0M3
    p: 15 students
    r: 3 students
    t: 19 students
    v: 19 students
    x: 1 students
    y: 2 students
    z: 2 students

    A sample "p" response (from student 0000), finding the final velocity of the conjoined carts from momentum conservation, and shows that the initial total kinetic energy is not equal to the final total kinetic energy:

    A sample "p" response (from student 1313), also finding the final velocity of the conjoined carts from momentum conservation, but instead showing that the loss of kinetic energy of the first cart is not equal to the gain in kinetic energy of the second cart:

    A sample "p" response (from student 0365), noting that the final velocities of the carts would be identical, such that the relative velocity form of the kinetic energy conservation equation for elastic collision can be directly shown to be invalid:

    Physics final exam problem: metal samples placed in water

    Physics 205A Final Exam, fall semester 2013
    Cuesta College, San Luis Obispo, CA

    Cf. Giambattista/Richardson/Richardson, Physics, 2/e, Practice Problem 14.5, Comprehensive Problem 14.95

    A 0.50 kg sample of iron at 95° C and a 0.75 kg sample of aluminum at 10° C are both placed in a container with 1.00 kg of water at 20° C. Find the temperature of the water after thermal equilibrium has been reached. Ignore the effects of evaporation and phase changes, and heat exchanged with the environment and container. Show your work and explain your reasoning using the properties of heat, temperature, and thermal equilibrium.

    Specific heat of iron is 440 J/(kg·K). Specific heat of aluminum is 900 J/(kg·K). Specific heat of water is 4,190 J/(kg·K).

    Solution and grading rubric:
    • p:
      Correct. Sets up an energy transfer/balance equation with changes in the thermal internal energies of the iron, aluminum and water summing to zero (no heat exchanged with container and environment), and solves for the final thermal equilibrium temperature of the system.
    • r:
      Nearly correct, but includes minor math errors.
    • t:
      Nearly correct, but approach has conceptual errors, and/or major/compounded math errors. At least has energy transfer/balance equation with three terms, but typically does not set up ∆T terms correctly.
    • v:
      Implementation of right ideas, but in an inconsistent, incomplete, or unorganized manner. At least some attempt at setting up change in internal energy terms and/or an energy transfer/balance equation.
    • x:
      Implementation of ideas, but credit given for effort rather than merit. No clear attempt at applying energy transfer/balance equation.
    • y:
      Irrelevant discussion/effectively blank.
    • z:
      Blank.
    Grading distribution:
    Sections 70854, 70855, 73320
    Exam code: finaln0M3
    p: 17 students
    r: 5 students
    t: 10 students
    v: 12 students
    x: 6 students
    y: 5 students
    z: 6 students

    A sample "p" response (from student 5678):

    A sample "p" response (from student 0618), first converting the initial temperatures to Kelvin, to find the final temperature in Kelvin:

    A sample "t" response (from student 0817):

    A sample "v" response (from student 0716):

    A sample "y" response (from student 8207):

    20140110

    Astronomy in-class activity: planet-hunting

    Astronomy 210 In-class activity 6 v.14.01.10, spring semester 2014
    Cuesta College, San Luis Obispo, CA

    Students find their assigned groups of three to four students, and work cooperatively on an in-class activity worksheet to determine where in the sky each naked-eye planet will be observed on a given date (here, February 6, 2014).



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