20161214

Online reading assignment question: advice to future students

Astronomy 210, fall semester 2016
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. The following question was asked after the last lecture, but prior to the final exam.

Tell a student who is about to take this course next semester what he/she needs to know or to do in order to succeed in this course. (Graded for completion.)
"Do all of the blogs and reading assignments before class and take advantage of office hours."

"Do all of the reading assignments and come to class! It is awesome!"

"Study the links P-dog gives before the midterms/final. They help immensely."

"The material may seem hard but there is no busy work in this class. There is a small amount of actual work and if you actually do it and understand it you will do well. P-dog knows his stuff and he knows what works. His grading system is awesome, because you really earn your grade. DO WHAT IS ASSIGNED FROM THE BEGINNING."

"Attend classes, do online homework, and studying."

"Show up, really care about what is going on and the subject matter, call him P-dog, ALWAYS do the homework, practice do all the above, and life in class will rock! I am thinking about taking more with P-dog, he's chill!"

"Re-read the quizzes, and make a study group!"

"The only thing you need to know is that you will be able to learn and have fun."

"Read the textbook, and take notes as you do. If you can read before the class presentations on the topic, you will be able to ask all the questions you need to. Take advantage of the quiz questions given to you to study."

"Reading assignments and show up to class."

"Relax and have fun don't overstudy, don't overestimate the difficulty of this course. read read read!! Do your online homework and go to class. Take thorough notes!!!"

"Do the online homework for cryin' out loud."

"Do all the online surveys and go to class for the participation points!"

"I would tell them to make sure to do the readings and ask questions in class if they did not understand something from the homework."

"Do the homework and study past tests for the midterms."

"Make sure to do the reading assignments ahead of time. I kept forgetting about them."

"In order to succeed study previous quizzes for the midterms."

"DO ALL THE READING ASSIGNMENTS. "

"In order to succeed in this course, ask questions. It may seem like cliché, but chances are someone is probably thinking the exact same thing."

"In order to succeed in this course, you only need a few basic tips. Stay on top of reading assignments, I would even go as far as saying to set reminders on your phone because it is simple to forget in the rush of things. I also suggest falling into the subject matter, do not just learn terms and definitions, instead this course challenges you to knowing things in depts. It is not a surface level subject, so you can not give surface level commitment. Also, just have fun, P-dog will have interesting and informational lectures that should help you without a doubt succeed in this course."

"You need to show up for class, participate, and study for quizzes and tests."

"It's very long at night."

"Yo, this isn't astrology, so get that out of your head. Show up to class, do the work, don't procrastinate, listen and take notes, study hard and this class is a breeze. Fail to do any of these steps and don't be surprised when your grade starts to slip. But hey, it's one night a week so it can't be to hard to stay on top of things."

"Really prepare for the quizzes and take advantage of office hours."

"Keep up with the assignments and show up to all the classes. Having the ability to ask questions really helps understand the information at the time, rather than skipping class and do the reading and not being able to clarify the parts you don't fully understand."

"Love the subject you're learning about, have a curious mind, and ask questions when you don't get it. (You have an awesome instructor and helpful group members around you to help you out!)"

"Learn how to take notes during long lectures and make sure to go to every class in order to do well in this course."

Online reading assignment question: advice to self for next semester

Physics 205A, fall semester 2016
Cuesta College, San Luis Obispo, CA

Students have a bi-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. The following question was asked after the last lecture, but prior to the final exam.

Give a piece of advice to yourself at the start of next semester on what you should do (the same, or differently) in order to succeed in Physics 205A/B (or similar science courses). (Graded for completion.)
"Reading blog posts and actually doing the homework assigned and the review problems for midterms."

"Read the book before the lectures."

"When I read the past comments at the beginning of this course I didn't realize how helpful one comment was, so pay attention: Before class READ THE BLOG! Before a quiz READ THE BLOG! Before a midterm or the final READ THE BLOG! And from my own experience: GO TO THE TUTOR and come prepared with questions (use the practice problems from homework to see where you need the most help) so you get the most out of the time spent there."

"Going to the tutor was the only reason I am passing this class!"

"It does not help to procrastinate, it is important to keep up with the homework and labs they really help."

"Don't read the book, it's useless. P-dog's blog is all the information you need. if you want to read the book just read the summary in the back and listen to the lecture. then go to the embedded tutor or the drop in tutor below the library. P-dog has formulas of the different concepts of each chapter, print those out and put them in a word document or something and go over them with the embedded tutor and label what each of the letter and symbol represent. Knowing what those symbols represent and drawing out the full-body diagram is about 75% of the credit right there."

"Several of my concepts of physics I realize were wrong before I took this course and understanding those new concepts was crucial to doing well."

"Getting into a group and studying."

"Something that does help is going to the embedded tutor. Also doing the practice problems on the blog helps. You really just gotta do it!"

"Doing the homework and the things before class is useful. I would also recommend going hard earlier rather than later so you can ease up towards the end."

"Understanding the material and trusting yourself."

"Knowing what the teacher is asking, and being able to replicate problems."

"By reading the review questions on the blog and actually trying to understand the reasoning of each of them helps while studying."

"Redoing the hardest problems, and working through them in detail really helped cement the concepts into my brain."

"What helped me study was doing the example problems given to us before an exam, that way I can find out what I need to work on and study that harder."

"It really doesn't help to procrastinate. I think that looking over the practice examples P-dog does on the board are the most helpful to study."

"Breathe."

"I think study groups really helped so maybe if there was a way to facilitate people meeting during the week to encourage learning. "

"What really helps is taking your time on the reading assignments on the blog, not just doing them for the sake of doing them/"

"P-dog's blog and worked-out problems online are probably the most helpful besides just reading the chapters."

"Studying all the problems posted on the blog that were related to the upcoming quiz or exam was extremely helpful because it forces you to think about the concepts in a critical/problem-solving way as you would on the exam or quiz."

"The practice quizzes are very helpful because a lot of it is material that will be on the actual quiz. Plus having the blog handy is also very helpful."

"What helps with this class is reading the book and doing the homework assignments before coming to class and coming prepared to do in class problems. That will make the class much easier. What won't help is not doing what I said in the first part. It can be a difficult class if you don't do any of that."

20161210

Physics quiz question: thermal contraction of lid and pot

Physics 205A Quiz 7, fall semester 2016
Cuesta College, San Luis Obispo, CA

"Pot Lid"
Mike Shoup
flic.kr/p/bjbrwB

A tempered glass lid (linear expansion coefficient 3.3×10–6 K–1) fits exactly with no gaps on an aluminum pot (linear expansion coefficient 23×10–6 K–1) at room temperature (20° C). If both the lid and the pot decrease in temperature to 10° C, the lid will:
(A) have a gap all around it.
(B) still fit exactly.
(C) be squeezed by the pot.
(D) (Not enough information.)

Correct answer (highlight to unhide): (C)

The relation between the change ∆L of a linear dimension L (here, diameter) due to a temperature change ∆T is given by:

α·∆T = ∆L/L,

such that for the lid and the pot:

Llid = L·αglass·∆T,

Lpot = L·αAl·∆T.

The original diameter of the lid and the pot at the initial temperature of 20° C is the same, and both lid and pot experience the same temperature decrease ∆T. Since the linear expansion coefficient for aluminum is greater than that of glass (αAl > αglass), then the diameter of the pot will contract more than the diameter of the lid (∆Lpot > ∆Llid), such that the lid will be compressed by the pot.

Sections 70854, 70855, 73320
Exam code: quiz07p4sT
(A) : 11 students
(B) : 7 students
(C) : 34 students
(D) : 0 students

Success level: 65%
Discrimination index (Aubrecht & Aubrecht, 1983): 0.50

Physics quiz question: equally-heated aluminum samples

Physics 205A Quiz 7, fall semester 2016
Cuesta College, San Luis Obispo, CA

"Aluminum Cube"
Cliff Hutson
flic.kr/p/rzdiCW

Two aluminum samples (0.50 kg and 0.75 kg) at 15.0° C are each separately given 15,000 J of heat. The two samples are then brought in contact with each other, and allowed to reach thermal equilibrium. Ignore heat exchanged with the environment. Specific heat of aluminum is 900 J/(kg·K). While reaching thermal equilibrium when brought in contact with each other (after each has separately been given 15,000 J of heat), heat flows from the __________ aluminum sample to the __________ aluminum sample.
(A) 0.50 kg; 0.75 kg.
(B) 0.75 kg; 0.50 kg.
(C) (No heat is exchanged.)
(D) (Not enough information is given.)

Correct answer (highlight to unhide): (A)

The transfer/balance energy conservation equation for each block is given by:

Qext = ∆Esmall = msmall·cAl·∆Tsmall,

Qext = ∆Ebig = mbig·cAl·∆Tbig.

Since both blocks have been given the same amount of heat Qext = +15,000 (the positive sign denoting thermal energy added into the block) and the same specific heat cAl, then the smaller 0.50 kg block will experience a greater increase in temperature, and be at a higher temperature than the 0.75 kg block after both have been heated up.

Thus when these two blocks are subsequently brought in contact with each other, then since the smaller 0.50 kg block is at a higher temperature than the 0.75 kg block, heat will then flow from the 0.50 kg block to the 0.75 kg block.

Sections 70854, 70855, 73320
Exam code: quiz07p4sT
(A) : 30 students
(B) : 14 students
(C) : 8 students
(D) : 0 students

Success level: 58%
Discrimination index (Aubrecht & Aubrecht, 1983): 0.93

Physics quiz question: thermal paste heat conduction

Physics 205A Quiz 7, fall semester 2016
Cuesta College, San Luis Obispo, CA

"thermal paste"
Hafizan Mohamad Noor
flic.kr/p/4Qx9Vz

The rate of heat conducted per time from a hot Intel® "Skylake"-H Core i7 computer chip, through a thin layer of thermal paste to a cooling unit is 45 watts[*]. Increasing just the thickness of the thermal paste layer would ___________ the rate of heat conducted per time through it.
(A) decrease.
(B) not change.
(C) increase.
(D) (Not enough information is given.)

[*] wki.pe/Skylake_(microarchitecture).

Correct answer (highlight to unhide): (A)

The thermal resistance R of an object can be related to its thermal conductivity κ by:

R = d/(κ·A),

where d is the thickness of the object that heat must conduct through, and A is the cross-sectional area. Increasing the thickness d of the thermal paste layer would then increase the thermal resistance R of this layer. The rate of heat per time conducted is given by:

Power = ∆T/R,

where the temperature difference ∆T is measured between the hotter chip and the cooler calling unit above it, and since increasing the thickness d of the thermal paste layer would increase the thermal resistance R of this layer, the rate of heat conducted through the layer would then decrease.

Sections 70854, 70855, 73320
Exam code: quiz07p4sT
(A) : 45 student
(B) : 1 student
(C) : 6 students
(D) : 0 students

Success level: 87%
Discrimination index (Aubrecht & Aubrecht, 1983): 0.29

Physics quiz question: radiating concrete columns cooling

Physics 205A Quiz 7, fall semester 2016
Cuesta College, San Luis Obispo, CA

"PKGarage"
Kelly Nighan
flic.kr/p/diq5GV

Two concrete columns (emissivity 0.85[*]) are at a temperature of 293 K, and are exposed all around their sides to an environment at a temperature of 273 K. The two columns have the same cross-sectional area, but the shorter column is one-half the length of the taller column. The __________ concrete column cools off faster due to the net amount of radiative heat per time transferred to/from the environment.
(A) shorter.
(B) taller.
(C) (There is a tie.)
(D) (Not enough information is given.)

[*] engineeringtoolbox.com/emissivity-coefficients-d_447.html.

Correct answer (highlight to unhide): (B)

The power (rate of heat per time) radiated is given by:

Power = –e·σ·A·((Tobj)4 – (Tenv)4),

Since both the short and tall concrete columns have the same emissivity e and temperature Tobj), and are both surrounded by the same environment temperature Tenv), the net rate of heat simultaneously radiated to and absorbed from the environment them differs only because of their surface areas:

Powershort = –(0.85)·σ·Ashort·((293 K)4 – (273 K)4),

Powertall = –(0.85)·σ·Atall·((293 K)4 – (273 K)4).

Since the taller column has more surface area (Atall > Ashort), then the taller column will have a greater net rate of heat radiated per time, thus cooling off faster than the shorter column (Powertall > Powershort).

(Note the negative values for power here, corresponding to a net amount of heat being removed (radiated) from the object, while a positive value corresponds to a net amount of heat being put into (absorbed) by the object (in order to be consistent with the ±Q convention for removing heat from (–) or putting heat into (+) a thermodynamic system).)

Sections 70854, 70855, 73320
Exam code: quiz07p4sT
(A) : 14 students
(B) : 23 students
(C) : 15 students
(D) : 0 students

Success level: 44%
Discrimination index (Aubrecht & Aubrecht, 1983): 0.72

20161209

Astronomy current events question: discovery of brown dwarf OGLE-2015-BLG-1319

Astronomy 210L, fall semester 2016
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!)
Elizabeth Landau, "NASA Space Telescopes Pinpoint Elusive Brown Dwarf" (November 10, 2016)
jpl.nasa.gov/news/news.php?feature=6673
NASA's Spitzer and SWIFT space telescopes discovered the brown dwarf OGLE-2015-BLG-1319 by observing how its gravity distorted light from:
(A) a nearby black hole.
(B) magnetic storms.
(C) its own fusion.
(D) our sun.
(E) a distant background star.

Correct answer: (E)

Student responses
Sections 70178, 70186
(A) : 1 student
(B) : 2 students
(C) : 3 students
(D) : 2 students
(E) : 18 students

Astronomy current events question: Chicxulub crater peak ring

Astronomy 210L, fall semester 2016
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!)
Alexandra Witze, "Rock Core from Dinosaur-Killing Impact Reveals How Enormous Craters Form" (November 18, 2016)
scientificamerican.com/article/rock-core-from-dinosaur-killing-impact-reveals-how-enormous-craters-form/
Rock samples from the Chicxulub crater reveal that the asteroid impact may have __________ granite deep within Earth.
(A) liquified and tossed upwards.
(B) produced diamonds in.
(C) magnetized.
(D) released fossil fuels from.
(E) been the origin of.

Correct answer: (A)

Student responses
Sections 70178, 70186
(A) : 12 students
(B) : 4 students
(C) : 1 student
(D) : 1 student
(E) : 8 students

Astronomy current events question: Mercury's Great Valley

Astronomy 210L, fall semester 2016
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!)
Lauren Lipoma, "Great Valley Found on Mercury" (November 16, 2016)
news.agu.org/press-release/great-valley-found-on-mercury/
The newly discovered Great Valley on Mercury may provide evidence of __________ caused by gradual shrinking.
(A) past asteroid impacts.
(B) earthquakes.
(C) crust distortions.
(D) flowing water.
(E) lava flows.

Correct answer: (C)

Student responses
Sections 70178, 70186
(A) : 0 students
(B) : 0 students
(C) : 21 students
(D) : 3 students
(E) : 1 student

20161208

Astronomy quiz question: metal-rich main-sequence stars

Astronomy 210 Quiz 7, fall semester 2016
Cuesta College, San Luis Obispo, CA

Metals are found in the outer layers of stars that started their main-sequence lifetimes:
(A) very recently.
(B) a long time ago.
(C) in metal-poor nebulae.
(D) in distant galaxies.

Correct answer (highlight to unhide): (A)

Stars produce metals (elements heavier than hydrogen and helium) in their cores during their giant/supergiant phases, up through type Ia/II supernovae explosions. Along with their unused hydrogen, these metals are then scattered into the interstellar medium, which are then incorporated into later generations of stars. An old, early generation star will have metals only in its core, while a young, later generation star will have metals sprinkled in its outer layers as well as in the core.

Section 70158
Exam code: quiz07sAOr
(A) : 28 students
(B) : 7 students
(C) : 2 students
(D) : 0 students

Success level: 77% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.18

Section 70160
Exam code: quiz07nt70
(A) : 23 students
(B) : 1 student
(C) : 0 students
(D) : 0 students

Success level: 96% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.20

20161207

Astronomy quiz archive: Milky Way, cosmology

Astronomy 210 Quiz 7, spring semester 2016
Cuesta College, San Luis Obispo, CA

Section 70158, version 1
Exam code: quiz07sAOr


Section 70158
0- 8.0 :   *** [low = 4.0]
8.5-16.0 :   *****
16.5-24.0 :   ************ [mean = 22.4 +/- 8.1]
24.5-32.0 :   **************
32.5-40.0 :   *** [high = 36.5]


Section 70160, version 1
Exam code: quiz07nt70


Section 70160
0- 8.0 :  
8.5-16.0 :   **** [low = 10.5]
16.5-24.0 :   ******** [mean = 23.1 +/- 5.9]
24.5-32.0 :   **********
32.5-40.0 :   ** [high = 36.0]

Physics quiz archive: temperature, thermal equilibrium, heat transfer

Physics 205A Quiz 7, fall semester 2016
Cuesta College, San Luis Obispo, CA
Sections 70854, 70855, 73320, version 1
Exam code: quiz07p4sT



Sections 70854, 70855, 73320 results
0- 6 :   * [low = 6]
7-12 :   *************
13-18 :   ***************
19-24 :   *************** [mean = 18.5 +/- 6.6]
25-30 :   ******** [high = 30]

Online reading assignment: origin of life, are we alone? (SLO campus)

Astronomy 210, fall semester 2016
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 the origin of life, a "Here Is Today" timeline, LEGO® washing tips and the extraterrestrial hypothesis.


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.
"How insignificant this day is on the scale of time."

"I found the timeline interesting, because it is crazy to think how much of a little slice of time modern humanity takes up."

"How atoms tend to hook up with one another also known as the Miller experiment."

"Did you seriously just give us a LEGO®-washing lesson, or am I that sleep deprived?"

"That one equation can show if there's life in the universe?!"

"That genetic mutations can kill the organism but at the same time some genetic mutations will be very beneficial if the environment changes in order to help that organism."

"The Drake formula, I can't believe an equation that is 50% 'SWAG' is considered legitimate and that people have the gall to assume humans are the only organisms capable of our kind of 'advancement.'"

"Crop circles, interesting because of the size and planning it would take a human to accomplish this, or perhaps an alien gardener was bored and has a sense of humor."

Describe something you found confusing from the assigned textbook reading or presentation preview, and explain why this was personally confusing for you.
"I found the Drake equation to be a little confusing, just because all the different factors area little confusing."

"The LEGO® thing and how it worked."

"I really didn't understand the Drake equation."

"Chemical evolution is one thing that I don't understand."

"So, it takes a lot to go from non-living to life?"

"How primordial soup composed of liquids being evaporated and energized over and over can create complex life."

"I'm skeptical about how one equation can give an estimation for the number of other life forms in the universe."

"How DNA instruction happen or exist, this is just mind-boggling."

"I am confused as to how the Cambrian explosion occurred? Was it just spontaneous?"

Briefly describe a difference between life and non-living things.
"Living things change with their surroundings."

"Life reacts to its surroundings, while none living things don't."

"Life must be able to eat, build, destroy, and adapt to things whereas non-living things are building blocks or simply molecules."

"Living things are bodies that create, destroy, eat, and/or change within a given period of time. Although the earth changes, it is not alive because it does not create a next generation to carry on information from past experiences."

"Be able to store and transmit data and make decisions for survival."

"All living things contain carbon, but not all things that contain carbon are living."

"I could not find the answer to this question in any of the presentations."

How important is it to you to know whether or not there may be life elsewhere other than on Earth?
Unimportant.  * [1]
Of little importance.  **** [4]
Somewhat important.  ******** [8]
Important.  ******* [7]
Very important.  **** [4]

Briefly explain your answer regarding the importance of knowing whether there may be life elsewhere other than on Earth.
"It is super important to me, because I find it hard to believe that we are the only intelligent life-form on the planet."

"It could change the way we understand life or knowledge."

"I think it's important to know for our own safety and maybe to further our intelligence as a species."

"Knowledge. We can gain so much more information and learn new things about the universe if we could communicate or know that there are other living things in the galaxy."

"It would be a HUGE learning experience if we found life elsewhere! Not to mention it would be really cool to know that we are not alone in this place. Or creepy..."

"This could be important to know because it can lead to chaos or salvation for our humankind. We are destroying ourselves by pollution and waste, but with the knowledge of other intelligent life we may be able to fix our way of life and other issues."

"It would be interesting to know but it is not so important because I'm not sure how this would change anything on Earth. If we consider what hollywood has portrayed I might be worried of an attack. But if there is life out there I feel it would not change things for Earth."

"I am personally curious but I do not think that it is necessarily the most important thing to know."

Which type of star would be least likely to have a planet that could support life?
Massive.  *************** [15]
Medium-mass.  *** [3]
Low-mass (red dwarf).  ****** [6]
(Unsure/guessing/lost/help!)  [0]

Briefly explain your answer to the previous question (type of star least likely to have a planet that could support life).
"A massive star would be least likely to support life because the lifetime would not be long enough for life to start."

"For massive stars, habitable zones are at huge distances where rocky planets are unlikely to form/ it would be hard for a planet to be that far from a star."

"A low-mass star wouldn't produce enough heat."

"Medium-mass stars give off enough heat and are stable at that heat for long enough time for life to grow. Massive stars change frequently and low-mass stars are...small."

"Stars with higher metallicity have more likely of a chance to have a planet capable of supporting life. Younger stars have more metallicity, therefore it is least likely for a low-mass star."

Describe what the Drake equation is used for.
"The Drake equation begins by having values then it becomes less reliable to estimate the number of technological civilizations in the Milky Way."

"We can use it to estimate the technological number of civilizations in the Milky Way galaxy."

"It is used for finding out the probability of life on other planets using an equation with a lot of variables that get less answerable as they go on."

"It is used to identify how many possible civilizations there are in the Milky Way and with which we can maybe talk to."

"To find life in our universe."

"I'm not sure."

In your opinion, how plausible is it that the Chilbolton message is a reply from extraterrestrials?
Implausible.  [0]
Not very plausible.  *********** [11]
Somewhat plausible.  ************ [12]
Very plausible.  [0]
(Unsure/guessing/lost/help!)  * [1]

Ask the instructor an anonymous question, or make a comment. Selected questions/comments may be discussed in class.
"I saw Arrival last night, and it was awesome."

"How do you organize a party in space? You planet. #hahahahahahahahahaha" (#smh)

"What is your favorite place you have ever traveled?" (There was this time that Mrs. P-dog and I went backpacking somewhere in Hawaii that looked like Mars.)

What is your opinion on the Chilbolton message? (There should have been souvenir t-shirts sold there, like the Fairfield crop circles in 2003.)

"Which should we be more worried of alien life or A.I.?" (Alien A.I.? #justsaying)

"How would you prepare for the final?" (The study guide for the final is now posted on the course website; so study for it like you did for the midterm.)

"I've literally been trying to bust out a ten-page research paper, on top of another essay and catch up on my math homework which is all due on the same day. I truly dislike finals!!! This class is so easy and I am looking forward to this final out of all my classes, but I am truly looking forward to getting more sleep once this is all over."

20161206

FCI pre-test to post-test comparison

Students at Cuesta College (San Luis Obispo, CA) were administered the 30-question Force Concept Inventory (David Hestenes, et al.) during the last week of instruction.

The pre- to post-test gain for this semester is:

Physics 205A fall semester 2016 sections 70854, 70855, 73320
<initial%>= 33% ± 15% (N = 60)
<final%>= 39% ± 17% (N = 48)
<g>= 0.10 ± 0.21 (matched-pairs); 0.10 (class-wise)

Student's t-test of the null hypothesis for Cuesta College FCI pre-test scores versus post-test scores results in p = 0.033 (t = –2.16, sdev = 4.69, degrees of freedom = 106), thus there is a statistically significant difference between Cuesta College FCI pre-test and post-test scores.

This Hake gain is comparable to (but slightly lower than) previous semesters' results for algebra-based introductory physics at Cuesta College (0.17-0.33), but similarly comparable to (but slightly lower than) previous gains for calculus-based introductory physics at Cuesta College (0.14-0.16), as discussed in previous postings on this blog.

Notable about this Physics 205A class at Cuesta College since fall semester 2015 is the presence of an embedded tutor (student teaching assistant circulating in class along with the instructor during open discussion and problem-solving sessions); and from fall semester 2014 onwards is the requirement that students read and answer questions on the textbook and lecture slides before coming to lecture (in a "flipped classroom"), instructor discussion in-class based on answering student questions and concerns submitted online previous to lecture, in-class problem-solving sessions ("lecture-tutorials," including ranking tasks, and a brief written explanation of a selected question submitted by each student every lecture), open-ended labs, and the continuing use (since fall semester 2011) of flashcards rather than electronic response system "clickers" (Classroom Performance System, einstruction.com), to engage in "think-pair-share" (peer-instruction).

D. Hestenes, M. Wells, and G. Swackhamer, Arizona State University, "Force Concept Inventory," Phys. Teach. 30, 141-158 (1992).
Development of the FCI, a 30-question survey of basic Newtonian mechanics concepts.

Previous FCI results:

Online reading assignment: origin of life, are we alone? (NC campus)

Astronomy 210, fall semester 2016
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 the origin of life, a "Here Is Today" timeline, LEGO® washing tips and the extraterrestrial hypothesis.


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 found the idea of the thought process of the possibility of life elsewhere was interesting. The crop designs, I found they were pretty amusing. But how did people figure out how to make the crop designs back in the day? Was someone standing on top of the building in the the middle of the night, guiding the person on the bottom with the tractor?"

"I liked watching the video on crop circles because I have always wondered if it was a possibility that they were not man-made. Crop circles, who made them."

"Life in the universe is super-interesting because we can learn the process of life in which organisms extract energy from the surroundings."

"That the evolution of molecules is similar to how humans have evolved because we like to think we are so different from everything else and are so unique."

"The behavior of atoms, their tendency to form molecules in the presence of energy."

"The Drake equation, I never knew such a thing existed."

"Just going through the time periods is interesting enough. Its amazing that humans have only been here for the shortest period of time compared to how old everything else is."

"The timeline of life and everything on Earth. It's a pretty cliché thing to be taken aback by, but it's for a good reason."

"I really enjoyed the LEGOS® in the washing machine. It is a good model to show how seemly randomness can create patterns and structure. (It was overly simplified but still impressive.)"

Describe something you found confusing from the assigned textbook reading or presentation preview, and explain why this was personally confusing for you.
"I found the Drake equation little confusing because I don't understand how they could figure a lot of those numbers out."

"Drake equation. I don't understand what it means."

"Why did Drake choose an anticoded pixel message? It that the only types of messages we blast into space?"

"I could use more explanations on the origin of life and specifically the Miller experiment."

"DNA--the code of life is super complicated. All of the processes in an organism."

Briefly describe a difference between life and non-living things.
"Well the simplest of life are long molecular chains that can replicate at a fast pace making themselves larger. Thus making plants or even ourselves growing and alive, unlike non-living things."

"Life is anything organic that can grow, react to changes, have to eat food for energy and can reproduce."

"Life is when it is able to manipulate its environment and is able to make new generations of itself."

"Living things with manipulate their environment and create a future generations which will also manipulate the environment."

"Living things attempt to manipulate their environment. Non-living things may have complicated chemicals and stuff, but if they don't interact with their environment, they aren't alive."

How important is it to you to know whether or not there may be life elsewhere other than on Earth?
Unimportant.  [0]
Of little importance.  ** [2]
Somewhat important.  ******** [8]
Important.  *** [3]
Very important.  ***** [5]

Briefly explain your answer regarding the importance of knowing whether there may be life elsewhere other than on Earth.
"Not really interested and if there is life elsewhere, I will probably not be able to see it within my lifetime. I'm fine with seeing extraterrestrial life through video games, it's enough for me to satiate my desire of seeing real extraterrestrial life."

"I'm just not really convinced there is life on other planets., not that I'm against knowing if there is. It's just something that's really hard to believe. And if there is, well it also depends what kind of life. Humans, aliens, plants?"

"Knowing how big the universe is there is no way that there is only life on Earth and it freaks me out that we have not seen any other life anywhere else."

"My curiosity stems from the idea that we're the only ones at all. This is the basis to many religious beliefs and I would like to know if they're wrong and if they are, what are the other living things like?"

"I think it is very important because chances are if the life is similar to ours they are probably much smarter and they could teach us a lot."

"It stretches my faith."

"In Scripture, it does not say if there are other planets with life, but we know God is the source of life, so if we find any, He put it there."

"It will be nice to know if there is life in other planets because that would change the whole world in a positive way."

"I believe that knowing the answer o this question could change humanity."

"If there is or isn't life elsewhere I think we should know about it and try to figure it out. We don't want any surprises."

"I believe self-preservation is a trait most humans share. Other forms of life may threaten our existence, as with the native peoples and the Europeans. However, if a peaceful and healthy relationship between humanity and alien life were to exist, it would be beneficial to both cultures. If there is any other life in the universe, it must be pretty simple. If there were complex civilizations, we should have run into them by now. However, if you're into conspiracy theories, we may already have, but just haven't been told."

Which type of star would be least likely to have a planet that could support life?
Massive.  ******** [8]
Medium-mass.  *** [3]
Low-mass (red dwarf).  *** [3]
(Unsure/guessing/lost/help!)  **** [4]

Briefly explain your answer to the previous question (type of star least likely to have a planet that could support life).
"It took about a billion years for life to appear in our planet, and a massive star runs out of hydrogen in just a couple million years, dying way before life can appear."

"A massive star will have a short lifetime (around a million yrs) and it takes simple life a very long time (billions) of years to develop. So a massive star will die before life on surrounding planets could develop."

"Because a massive star wouldn't have a long enough life span. Assuming life evolves. And isn't created."

"Massive stars do not have a long life span, the stars will expand its fuel rapidly, and go supernova which makes the probability of life impossible."

"Massive stars die out pretty fast, therefore exterminating any chance at life."

"I said massive because I feel like the big stars are never the ones that have habitable zones."

"Low-mass stars would be least likely because of its temperature."

"Medium-mass stars would be of the same age as a planet with life."

Describe what the Drake equation is used for.
"The Drake equation is used to estimate the number of advanced technological civilizations in the Milky Way."

"It multiplies factors of limitations set on the possibility of extraterrestrial life existing, within the Milky Way. It is used to hypothesize what the odds of intelligent life existing elsewhere in our galaxy."

"The Drake equation is used to estimate the number of communicating civilizations in the cosmos, or more simply put, the odds of finding intelligent life in the universe. N = the number of civilizations in the Milky Way galaxy whose electromagnetic emissions are detectable."

"The Drake equation is used to estimate the number of advanced technological civilizations in the Milky Way. Unfortunately, it cannot be solved."

"To narrow down the search for advanced life."

"I'm not sure how Drake equation is used."

In your opinion, how plausible is it that the Chilbolton message is a reply from extraterrestrials?
Implausible.  *** [3]
Not very plausible.  ********** [10]
Somewhat plausible.  **** [4]
Very plausible.  * [1]
(Unsure/guessing/lost/help!)  [0]

Ask the instructor an anonymous question, or make a comment. Selected questions/comments may be discussed in class.
"This is probably one of the more memorable sections, for sure one of the most interesting."  
"What is your favorite fictional alien race from movies, TV, or literature? What is your favorite movie having to do with astronomy (in any form) do to the accuracy of the movie's events?" (A recent favorite is Arrival, especially in the unexpected and inscrutable nature of communicating with an alien species.)

"The LEGO® thing blows my mind." (Try it for yourself!)

"Do you believe in aliens? Do you believe there is life on other planets? How would that affect your opinion if you found out there is life on other planets?" (Yes. I would bet maybe, like, $5 on there being life on other planets. And when we do make and confirm that discovery, then teaching astronomy will forever be even more awesome than it is already.)

20161205

Online reading assignment: heat transfer applications

Physics 205A, fall semester 2016
Cuesta College, San Luis Obispo, CA

Students have a bi-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 heat transfer applications.

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.
"How the Coffee Joulies work--their melting point is 140 and they turn into liquid and absorb the heat from the coffee and release it back when it begins getting cooler."

"We will be testing out some stuff related to the transfer of heat between different objects. I know that heat goes from hot to cold, so I am curious to see how the different things mentioned perform when tested."

"A Cooper Cooler chills wine in six minutes by spraying the bottle with ice water transferring heat to the ice water from the bottle. Coffee Joulies keep coffee at a comfortable 140° because the material inside the joulies has a melting temp of 140°. The solid material absorbs the heat of the coffee and releases a little bit at a time as the environment removes heat from the coffee."

"I've heard about space blankets before and how they are so light weight and not even expensive. They are a heat-reflective thin plastic sheet."

"That you lose a lot of body height from emitting it so an emergency space blanket should be silver."

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.
"There are no equations so I am confused if this will mostly be conceptual rather than a numerical section?"

"I am confused about carbonation when using a Cooper Cooler. Why does pressure build in a soda can when you shake it and not when you spin it?"

"I'm a little confused how spinning a bottle is any different than shaking it. It seems like the drink would still explode because it was still shaken up."

"How do I know it's conduction, convection or radiation for the questions below? I wasn't sure on how to know."

"I don't really understand how something can cool off faster by being spun and sprayed. It doesn't seem like it should work that well."

"It seems super interesting this method of adding Coffee Joulies to cool down your hot coffee while keeping it at a constant temperature. I don't fully understand how the coffee joulies work though and the chemical processes behind it."

The primary heat transfer process that the Cooper Cooler™ uses to chill beverages is:
conduction.  ***************** [17]
convection.  ************** [14]
radiation.  [0]
(Unsure/guessing/lost/help!)  **** [4]

How plausible do you think these claims for the Cooper Cooler™ are?
(Only modal responses shown.)
"The Cooper Cooler™ can chill a soda in one minute": somewhat plausible [43%]
"Because it's spinning and not shaking your carbonated beverages, you don't have to worry about them exploding": not very plausible [43%]

The primary heat transfer process that the Coffee Joulies™ uses to moderate and maintain coffee temperatures is:
conduction.  ********************** [22]
convection.  ********* [9]
radiation.  ** [2]
(Unsure/guessing/lost/help!)  ** [2]

How plausible do you think these claims for Coffee Joulies™ are?
(Only modal responses shown.)
"One 'bean' for every four ounces of coffee cools right down to 140° in a few seconds": somewhat plausible [49%]
"Keeps coffee at 140° for two full hours": not very plausible [37%]

The primary heat loss process that any blanket (regardless of type) should prevent in typical "emergency survival conditions" (on Earth) is:
conduction.  **** [4]
convection.  ******* [7]
radiation.  ******************** [20]
(Unsure/guessing/lost/help!)  **** [4]

How plausible do you think heavy-duty garbage bag material will be just as effective as a space blanket for typical "emergency survival conditions" on Earth?
Implausible.  ***** [6]
Not very plausible.  ******* [7]
Somewhat plausible.  ************** [14]
Very plausible.  ***** [5]
(Unsure/guessing/lost/help!)  [3]

Ask the instructor an anonymous question, or make a comment. Selected questions/comments may be discussed in class.
"The negative sign that is applied to the power equation for radiation--is that strictly for when energy is taken from the object?" (Yes, since a positive sign is for when energy (heat) is given to an object.)

"It says the emergency space blankets are perfect for space because radiative heat loss is the primary means of heat loss. What is the primary means of heat loss on Earth?" (Medical research says for a patient on an operating room table, it's radiation. But if you're wearing clothes, then you've minimized radiation and conduction (by covering up exposed skin and adding layers), and then you would need to minimize convection by sheltering yourself from the wind, and wearing a hat on your head. Heat loss via evaporation is an additional factor if you are perspiring (or even just exhaling), and are surrounded by dry (and cooler) air.)

"Could you just use a few extra trash bags instead, and it would be just as effective as a space blanket?" (Let's test this in lab, before you need to resort to this in the wilderness.)

"Would silverbody blankets be ideal for space?" (NASA seems to think so. And they use gold foil instead of aluminum foil, because, reasons.)

"I might need this Cooper Cooler if it really works." (Let's test this in lab, before you ask Santa for one of these.)

20161202

Physics final exam question: thermal expansion of pendulum string

Physics 205A Final Exam, fall semester 2015
Cuesta College, San Luis Obispo, CA

A Physics 205A student builds a simple pendulum using a string and a mass, and at a certain temperature it has a period of 1.50 s. As the temperature increases, determine whether the period will increase, decrease, or remain the same. Ignore friction/drag, and only consider the thermal expansion of the string. Explain your reasoning using the properties of simple harmonic motion and thermal expansion.

Solution and grading rubric:
  • p:
    Correct. Discusses how the period of a simple pendulum depends on the gravitational acceleration constant (which does not change) and the string length (which expands due to the increase in temperature), such that the period will increase.
  • 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 garbled attempt at applying thermal expansion to the simple pendulum parameters.
  • x:
    Implementation/application of ideas, but credit given for effort rather than merit. Approach other than applying thermal expansion to the simple pendulum parameters.
  • y:
    Irrelevant discussion/effectively blank.
  • z:
    Blank.
Grading distribution:
Sections 70854, 70855, 73320
Exam code: final7rUk
p: 47 students
r: 1 students
t: 15 students
v: 6 students
x: 2 students
y: 0 students
z: 0 students

A sample "p" response (from student 5612):

Astronomy current events question: "nearly naked" supermassive black hole

Astronomy 210L, fall semester 2016
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!)
Dave Finley, "Close Galactic Encounter Leaves 'Nearly Naked' Supermassive Black Hole" (November 2, 2016)
public.nrao.edu/news/pressreleases/nearly-naked-supermassive-black-hole
The Very Long Baseline Array (VLBA) discovered that B3 1715+425 is a "nearly naked" supermassive black hole, which may be the remnant of a galaxy that:
(A) fit inside of its own event horizon.
(B) passed through a larger galaxy.
(C) was composed of antimatter.
(D) devoured all of its own stars.
(E) had dead spiral arms.

Correct answer: (B)

Student responses
Sections 70178, 70186
(A) : 2 students
(B) : 8 students
(C) : 2 students
(D) : 8 students
(E) : 1 student

Astronomy current events question: computer models of moon orbit tilt origin

Astronomy 210L, fall semester 2016
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!)
Matthew Wright, "New Model Explains the Moon’s Weird Orbit" (October 31, 2016)
umdrightnow.umd.edu/news/new-model-explains-moon’s-weird-orbit
Computer simulations may explain Earth's axis and the moon's orbital tilts today assuming that __________ after the large impact that formed the Earth-moon system.
(A) Earth's axis was steeply tilted.
(B) multiple moonlets were created.
(C) magnetic fields were disrupted.
(D) the sun was highly unstable.
(E) volcanic activity ceased.

Correct answer: (A)

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

Astronomy current events question: proposed Bio-Indicator Lidar Instrument

Astronomy 210L, fall semester 2016
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!)
Lori Keesey, "New Instrument Could Search for Signatures of Life on Mars" (November 1, 2016)
nasa.gov/feature/goddard/2016/new-instrument-could-search-for-signatures-of-life-on-mars/
A proposed Bio-Indicator Lidar Instrument (BILI) would be used by future Mars rovers to remotely detect organic particles in:
(A) cloud ice crystals.
(B) underground water deposits.
(C) gases trapped in rocks.
(D) ancient fossils.
(E) dust plumes.

Correct answer: (E)

Student responses
Sections 70178, 70186
(A) : 2 students
(B) : 6 students
(C) : 2 students
(D) : 1 student
(E) : 9 students