20111130

Physics midterm problem: hydrostatic weighing

Physics 205A Midterm 2, fall semester 2011
Cuesta College, San Luis Obispo, CA

Cf. Giambattista/Richardson/Richardson, Physics, 2/e, Problems 9.37, 9.38

[20 points.] The average density of a person can be found by first weighing that person in air and then finding the scale reading for the person completely immersed in water (while suspended from the scale). If a person has a weight 550 N in air and has an average density of 1.05×103 kg/m3, what would be the scale reading for the person completely immersed in water? The density of water is ρwater = 1.00×103 kg/m3. Show your work and explain your reasoning.

Solution and grading rubric:
  • p = 20/20:
    Correct. Finds volume of person, given density and mass (from weight in air), and calculates bouyant force on person while submerged in water. The scale reading is then the difference between the weight and the bouyant force. Proper use of Newton's first law, definition of bouyant force, and relation between mass and weight.
  • r = 16/20:
    Nearly correct, but includes minor math errors. May have conflated mass and weight, or density values, but still clearly shows methodical process.
  • t = 12/20:
    Nearly correct, but approach has conceptual errors, and/or major/compounded math errors.
  • v = 8/20:
    Implementation of right ideas, but in an inconsistent, incomplete, or unorganized manner. At some attempt at using Newton's laws, definition of bouyant force, and relation between mass and weight.
  • x = 4/20:
    Implementation of ideas, but credit given for effort rather than merit. Discussion not based on methodical application Newton's laws, definition of bouyant force, and relation between mass and weight.
  • y = 2/20:
    Irrelevant discussion/effectively blank.
  • z = 0/20:
    Blank.

Grading distribution:
Sections 70854, 70855
Exam code: midterm02fR3q
p: 24 students
r: 4 students
t: 5 students
v: 8 students
x: 7 students
y: 0 students
z: 0 students

A sample "p" response (from student 3737), rounding to two significant figures during each step:
Another sample "p" response (from student 3737), rounding to two significant figures only for the very last calculation:

Physics midterm problem: bullet embedding into block

Physics 205A Midterm 2, fall semester 2011
Cuesta College, San Luis Obispo, CA

Cf. Giambattista/Richardson/Richardson, Physics, 2/e, Problems 7.43, 7.44

A 0.0036 kg Nosler® Ballistic Tip V-Shok .223 Remington bullet[*] is shot horizontally with a speed of 988 m/s and collides into a 2.6 kg block of wood. The bullet embeds itself in the block, and the block with embedded bullet together slide along a horizontal frictionless surface. What is the final kinetic energy of the sliding block and embedded bullet system? Show your work and explain your reasoning using properties of collisions, energy (non-)conservation, and momentum conservation.

[*] federalpremium.com/products/compare/rifle_compare.aspx.

Solution and grading rubric:
  • p:
    Correct. Applies momentum conservation to the perfectly inelastic collision between bullet and block to find the final velocity of bullet/block, and then calculates the final kinetic energy of bullet/block.
  • r:
    Nearly correct, but includes minor math errors. Momentum conservation applied to successfully find the final velocity of bullet/block, problematic kinetic energy calculation.
  • t:
    Nearly correct, but approach has conceptual errors, and/or major/compounded math errors. Only momentum conservation applied to successfully find the final velocity of bullet/block. No kinetic energy calculation.
  • v:
    Implementation of right ideas, but in an inconsistent, incomplete, or unorganized manner. Garbled attempt at momentum conservation, may or may not have kinetic energy calculation.
  • x:
    Implementation of ideas, but credit given for effort rather than merit. Does not apply momentum conservation.
  • y:
    Irrelevant discussion/effectively blank.
  • z:
    Blank.

Grading distribution:
Sections 70854, 70855
Exam code: midterm02fR3q
p: 24 students
r: 4 students
t: 5 students
v: 8 students
x: 7 students
y: 0 students
z: 0 students

A sample "p" response (from student 4816):

20111129

Education research: college physics midterm statistics

Cuesta College Physics 205A (college physics, algebra-based, mandatory adjunct laboratory) students students take their second midterm in the 15th week of instruction.

The midterm consists of five multiple-choice questions, two short-answer questions, and two worked-out problems, to be completed within 80 minutes (the length of a regularly-scheduled lecture).

Grading statistics:
Cuesta College
Physics 205A fall semester 2011 sections 70854, 70855
Exam code: midterm02fR3q
Midterm 2 results (N = 53, max score = 75):
0-15 :
16-30 : ** [low = 22]
31-45 : ***************
46-60 : ****************** [mean = 52.2 +/- 12.3]
61-75 : ****************** [high = 72]
The order in which students turned in their completed midterms was recorded, beginning approximately 20 minutes after starting, to 80 minutes after starting. With a linear regression r2 value of 0.0434, there is no significant correlation between the completion order c turning on the midterm and resulting score S (S = -0.1685c + 56.966).

20111128

Astronomy midterm question: supergiants larger than same-temperature main-sequence stars?

Astronomy 210 Midterm 2, fall semester 2011
Cuesta College, San Luis Obispo, CA

An astronomy question on an online discussion board[*] was asked and answered:
24gurl: How do astronomers conclude that a supergiant star is larger than a main-sequence star of the same temperature?
Roger: The supergiant star is more luminous than the main sequence star of the same temperature. The only way that a supergiant could be more luminous than the main sequence star is if it is larger, the luminosity is proportional to the star's area...
Discuss whether or not if this answer is correct, and how you know this. Explain using Wien's law, the Stefan-Boltzmann law and/or an H-R diagram.

[*] answers.yahoo.com/question/index?qid=20100217203829AADBeYk.

Solution and grading rubric:
  • p:
    Correct. Uses Stefan-Boltzmann law and/or interprets H-R diagram to show that supergiants must be larger than main sequence stars of the same temperature in order to be more luminous than the main sequence stars.
  • r:
    Nearly correct (explanation weak, unclear or only nearly complete); includes extraneous/tangential information; or has minor errors.
  • t:
    Contains right ideas, but discussion is unclear/incomplete or contains major errors.
  • v:
    Limited relevant discussion of supporting evidence of at least some merit, but in an inconsistent or unclear manner. At least attempts to use Wien's law, H-R diagram and/or the Stefan-Boltzman law.
  • x:
    Implementation/application of ideas, but credit given for effort rather than merit. Discussion not based on Wien's law, H-R diagram and/or the Stefan-Boltzman law.
  • y:
    Irrelevant discussion/effectively blank.
  • z:
    Blank.
Grading distribution:Section 70158
Exam code: midterm02s3Ar
p: 16 students
r: 5 students
t: 3 students
v: 9 students
x: 0 students
y: 1 student
z: 0 students

A sample "p" response (from student 1210), with a bonus illustration:

20111127

Education research: introductory astronomy midterm statistics

Cuesta College Astronomy 210 (introductory astronomy lecture) students take their second midterm on spectra, stars, galaxies and cosmology in the fourteenth/fifteenth week of instruction.

The midterm consists of ten multiple-choice questions (with partial credit for multiple-choice), and three short-answer questions (graded with a standardized rubric), to be completed within 80 minutes (the length of a regularly-scheduled lecture).

Grading statistics:
Cuesta College
Astronomy 210 fall semester 2011 section 70158
Midterm 2 results (N = 34, maximum possible score = 100):
0- 20.0 :
20.5- 40.0 : ** [low = 38.0]
40.5- 60.0 : *************
60.5- 80.0 : ********* [mean = 66.1 +/- 16.9]
80.5-100.0 : ********** [high = 96.5]
One student was excluded from the linear regression due to taking the midterms at other scheduled times (and thus was not ordered with the rest of the class). With a linear regression r2 value of 0.0296, there is no significant correlation between the completion order c turning on the midterm and resulting score S (S = 0.2791c + 61.108).


Grading statistics:
Cuesta College
Astronomy 210 fall semester 2011 section 70160
Midterm 2 results (N = 28, maximum possible score = 100):
0- 20.0 :
20.5- 40.0 : ** [low = 39.0]
40.5- 60.0 : *****
60.5- 80.0 : ************ [mean = 70.8 +/- 16.9]
80.5-100.0 : ********* [high = 96.0]
Four students were excluded from the linear regression, two from clerical errors in recording their completion order, and two due to taking the midterms at other scheduled times (and thus were not ordered with the rest of the class). With a linear regression r2 value of 0.0562, there is no significant correlation between the completion order c turning on the midterm and resulting score S (S = 0.532c + 66.663).

Online reading assignment question: helpful/unhelpful Midterm 2 astronomy study tips

Astronomy 210 Reading Assignment 12, fall semester 2011
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.

Describe something notable that either helped or did not help with studying for this midterm. Selected comments may be discussed in class. (Graded for completion.)

The following are all of the student responses to this question, verbatim and unedited.
"What does CMB look at again?"

"no question"

"what movie are we going to watch on extra credit day?"

"Can we do lots of flashcard questions in class on Monday?"

"No comment"

"Do you like In-N-Out?"

"if you were to take the midterm, would you get 100%?"

"What inspired you to teach astronomy?"

"Flashcard questions definitely help me understand the material better."

"No questions."

"i cant it would be helpful to get our activies back to study instead of the blank one on online"

"I don't have one this week, thank you"

"what is your favorite type of star"

"What is your favorite part of Astronomy?"

"How long have you been teaching?College? High school? Other?"

"None"

"No comment."

"Can we go over all or most of the flash card questions?"

"Was Jupiter going to become another sun and is one of Jupiter's moon like an early earth?"

"I'll give it my best like I did on the last midterm."

"Superman can fly at diffferent speeds. Explanation?"

"Do worms holes actually exist and is possible to travel using them?"

"good luck everyone!"

"none."

"Can you go easy on us please?"

"Can you devote this up coming class to pure review and the next one midterm?!"

"did you play sports in high school or college?"

"Thanksgiving is next week!"

"None"

"Monsters vs Aliens...whats real and whats a bunch of bull?"

"Can you make a detailed list for what we need to know for the final?"

"Yay for extra credit!"

"iPhone Or droid?"

"how was you week?"

"like that there is a review before the midterm"

"A please... :)"

"surprise super muffin party. please?"

"whats your favorite Thanksgiving dish?"

"What's the multiverse theory?"

"yo ho ho"

"once again, why r we still doing this?"

"Do you watch LOST?"

"cant think of a comment"

Online reading assignment question: confusing Midterm 2 astronomy topics

Astronomy 210 Reading Assignment 12, fall semester 2011
Cuesta College, San Luis Obispo, CA

111127-Astr210-Midterm2-confusing
http://www.flickr.com/photos/waiferx/6416615959/
Originally uploaded by Waifer X

Wordle.net tag cloud for confusing topics covered in Midterm 2, generated by responses from Astronomy 210 students at Cuesta College, San Luis Obispo, CA (http://www.wordle.net/show/wrdl/4480693/Untitled).

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.

List at least three words describing confusing subjects covered in class (up through this midterm). (Graded for completion.)

[Responses have been edited to consolidate related common subjects.]

Student responses
Sections 70158, 70160
redshifts, antimatter, matter
spiralarms, supernovae, darkmatter
stars evolution, blackholes, neutron stars
halolusters, bigbang, darkmatter
greenhouseeffect, platetectonics, quantummechanics
reionization, gaps, pairproduction
Sun photosphere chromosphere corona, spectra, stars evolution
Sun, atoms
bigbang, milkyway spiralarms
space, stars, darkmatter
dontknow
fusion, nebulae, blackholes
reionization
spiralarms, antimatter, darkmatter
Jovian, parsecs, arcseconds
stars evolution, giants, mainsequence stars
lookbacktime, lighttravel
supernovae
Wienslaw, StefanBoltzmann, darkmatter
fusion, density, nucleosynthesis
bigbang, spectrum, luminosity
supernovae, planets, platetectonics
everything
planets formation atmospheres gases, stars formation, bigbang
darkmatter, blackholes, galaxies
Mercury Moon
bigbang universe, everything dontknow photons
stars evolution, darkmatter, lookbacktime
nothing
StefanBoltzmann redshift greenhouseeffect
fusion, parsecs, stars
researchquestions
parsecs, haloclusters, disk halo stars
spiralarms, galaxies, spiralarms
bigbang, stars, space
darkmatter, fusion, mainsequence stars
annihilation, recombination, reionization, nucleosynthesis, pairproduction
dontknow
lightspeed, housepartymodel, mainsequence stars
haloclusters, spiralarms, terrestrial planets
stars evolution
nothing
galaxies, spiralarms, stars, stuff
stuff, giants, stuff


Describe your most confusing subject, and briefly explain why this subject confused you. (Graded for completion.)

The following are all of the student responses to this question, verbatim and unedited.
"The timeline of how the universe is believed to have been formed is confusing with all of the details that must be remembered"

"spiral arms are most confusing because i never fully understood how some parts of a galaxy are formed."

"massive star death, had trouble remembering each one"

"Globular clusters, I am unclear as to what they are and will have to read up about them before the midterm."

"I still don't understand how electrons jump up or emit."

"The things that I mentioned above this question are the main topics that are confusing to me. I just don't get it :/"

"the sun's layers, because they all are so close together and I had never thought of the sun as three separate things before."

"There was a lot to cover about the sun and how generally functions"

"The most confusing subject would be the Big Bang because it is hard to grasp how the universe began."

"Dark matter because we know it's there but don't know what it is."

"i get the all the concepts nothing pops out at me"

"I will be honest, the whole thing is confusing"

"big bang theory and the expansion of space"

"Spiral arm are confusing because I missed that day in class."

"There isn't anything that's super confusing."

"medium mass stars"

"It was kind of hard understanding and calculating the age of star and figuring out its lookback time."

"I just missed the lecture on supernova"

"I would say Wien's law and Stefan's law. I always seem to get stuck on mixing these two laws up and forgeting what the difference is between them."

"The origins of the universe is a bit confusing with having to indicate what created what with the photons indicating the mass of the universe."

"luminosity, temp, and size"

"..."

"Dont own the book."

"big bang, insane trying to imagine it"

"blackholes, it doesn't make sense that so much mass can be condensed into the same amount of space."

"I just need to learn more about them I'll study well"

"^ I always think I'm prepared for it, but the questions you ask always seem se=o detailed and i don't have all the answers. I'm trying to hard."

"the birth life and death of stars for some reason just confuses me."

"I dont think anything will be that confusing"

"I had to make sure to memorize the equation for the Stephan-Boltzmann Law. It's not always easy to remember off-hand."

"To me a confusing subject was at what time what part of our galaxy we will be able to see"

"The essay questions"

"The disc and halo stars is the most confusing to me because of the different terms for both of them in the book."

"It's hard to explain why the galaxy is flat and wide. The milky way is also a tough subject to describe."

"how far things are..."

"fusion just gets confusing with the protons and how they work"

"remebering all the steps in each pase of each stars life and the big bang"

"my most confusing subject black radiation. i didn't get much out of the book about it."

"The light speed threw me off guard with the years and detail of the telescopes."

"How the spiral arms in galaxies form. I just don't get it"

"I couldn't touch any of it.. i'm a hands on learner"

"vague questions posed on exams."

"I'm confused about some of the galaxy swirls and arms and how to tell if the shape based on those."

"progression of stars sooo much memorization"

Online reading assignment question: interesting Midterm 2 astronomy topics

Astronomy 210 Reading assignment 12, fall semester 2011
Cuesta College, San Luis Obispo, CA

111127-Astr210-Midterm2-interesting
http://www.flickr.com/photos/waiferx/6416615699/
Originally uploaded by Waifer X

Wordle.net tag cloud for interesting topics covered in Midterm 2, generated by responses from Astronomy 210 students at Cuesta College, San Luis Obispo, CA (http://www.wordle.net/show/wrdl/4480562/Untitled).

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.

List at least three words describing interesting subjects covered in class (up through this midterm). (Graded for completion.)

[Responses have been edited to consolidate related common subjects.]

Student responses
Sections 70158, 70160
dense, warm, monolithic
bigbang, MilkyWay, lookbacktime
bigbang, mainsequence, terrestrial planets
expansion, MilkyWay, bigbang
photons, darkmatter, and blackholes
greenhouseeffect, blackholes planets
MilkyWay, stars, luminosity, bigbang
Sun, formation stars MilkyWay
starclusters, bigbang
space, stars, gravity
galaxies, evolution Sun
awesome, confusing, loud
stars galaxies universe
lithium, supernovae, blackholes
MilkyWay, terrestrial, planets
blackholes, darkmatter, halo
galaxies, MilkyWay, collapse
lookbacktime
darkmatter, supernovae, blackholes, planetarynebulae
luminosity, nebula, spiralarms
housepartymodel, PimpStarRims, Haterade
supernovae, bigbang, MilkyWay
bigbang, universe, blackholes, antimatter
platetectonics, lightyears, stars evolution
stars, darkmatter, blackholes
stars housepartymodel
blackholes, planets darkmatter
MilkyWay, galaxies, stars
extrasolar planets, galaxies, stars evolution
nebulae galaxies stars evolution
space darkmatter
heattransfer research temperature difference
nebulae, mainsequence stars, terrestrial planets
bigbang time craziness
time, space, stars
moonphases, constellations, galaxies
stars bigbang lookbacktime
pulsars, nebulae, novae
mass, bigbang, greenhouseeffect
bigbang, darkmatter, antimatter
convection, craters, yeah
bigbang universe, blackholes, antimatter
blackholes, galaxies, stars
mainsequence, stuff, blackholes


Describe your most interesting subject, and briefly explain why this subject interested you. (Graded for completion.)

The following are all of the student responses to this question, verbatim and unedited.
"Formation theories behind galaxies. Looking at all of the colorful details really looked awesome"

"look back time is the most interesting because the stars we see now in the sky were made years ago"

"Big bang, it explains how the universe was created"

"The Milky Way because it is our galaxy."

"Black holes, because they bend space time."

"Black holes are interesting to me. They're just awesome!"

"the Big Bang, because I didn't ever really understand how everything supposedly started out, and now it all makes a lot more sense."

"The Milky Way, because I did not realize how enormous it really is."

"The most interesting subject for me would have to be the Milky Way, mainly because it is where the Earth is located and that it does affect us."

"How the universe is expanding. It's mind-boggling."

"the galaxy how we r able to see i did not know how limted we r and how big everything else is"

"the moon phase, I like to watch the moon"

"star formation"

"The beginning of the universe, specifically the creation of Lithium and the fact that more is not being made any where in the universe"

"I like learning about the Milky Way"

"Look back time into the universe because it's interesting to see how everything was before the big bang"

"I loved learning about the different aspects of galaxies, and how our galaxy was formed."

"I thought that it was cool that you could see into the past even though it has changed to the present."

"I found supernovas to be interesting because before we went over it I thought that it was something that just happens to stars when something goes wrong. I had no idea that they were one of the causes on how a new solar system is formed."

"The look-back times of stars was intriging because it indicates that not only does a star give light even when it's dead, but how expansive the universe is with how long the light travels."

"Features of other planets/ plate tectonics"

"..."

"creation of the universe, its pretty interesting to find out how it was all created and how it all works."

"big bang, the creation of who and what we are"

"dark matter, it's interesting and mysterious."

"Frequency of stars..it's nice to know what stars are out there"

"Black Holes"

"the different planets in relation to ours."

"I find all three things interesting because I've never studied them before"

"I was most interested in how spiral arms are formed in galaxies. It was fascinating to learn how they can be created when a galaxy devours smaller star clusters."

"The concept of our place in our galaxy and just how small our planet truely is in comparison"

"Big bang How the earth and it's moons got here"

"I thought the Nebula's were the most interesting because of the different kinds and the different ways they are produced."

"I loved learning about the big bang because I got to argue with my mom's jerk fiancé about it."

"The big bang, because its how we came to be"

"big bang, i always wondered what started it all and how and the details"

"Stars life and death and how they come n leave to"

"nebula, because it's an awesome sounding word."

"The Big Bang would have to be the most interesting, because it is a big part of history and its interesting to know how it happened."

"How we think the big bang happened because of the whole anti matter thing and how all of the matter in our universe is from a mistake"

"I enjoyed learning about convection and different laws because it had real world application"

"creation of the universe, its pretty interesting to find out how it was all created and how it all works."

"I enjoyed learning about the big bang; it's a subject that is universally (no pun intended) known, yet I had no idea the real event."

"supernova awesome"

Online reading assignment question: helpful/unhelpful Midterm 2 physics study tips

Physics 205A Reading Assignment 24, fall semester 2011
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.

Describe something notable that either helped or did not help with studying for this midterm. Selected comments may be discussed in class. (Graded for completion.)

The following are all of the student responses to this question, verbatim and unedited.
"Practice practice practice"

"studying with __________"

"Studying in chunks so it's not so overwhelming and cramming can be avoided."

"working out problems in class on thursday"

"focus helps, procrastination doesn't"

"It helps to study with other people... It also helps to do some of the homework problems and quiz problems again. It does not help when you are completely lost and can't make sense of physics."

"Flashcards and reviewing quizzes helps."

"study groups."

"Skyrim"

"Going through homework problems again and re-taking the quizzes/ flashcard questions."

"to study"

"it doesnt help when its boring it tends to make you not want to study"

"Please email the student an in detailed study guide with needed formulas and an actually list of things we need to know. the book is extremely messy"

"having multiple midterms at once doesnt help this class. i need to study physics"

"Ask for help if you don't know what the question is asking/giving. Examine the applicable formulas and check off what you know."

"Wheaties.nuff said"

"reviewing old quizzes helps me."

"Homework"

"tutor and just do problems"

"Flashcard questions only help a little. Doing more problems help a lot more. Not only from the book because the book problems can be confusing, but also maybe made up problems from you."

"Going over all of the homework for the chapters that will be on the midterm help a lot."

"Doing practice problems similar to the ones on the class calendar to get more practice on the specific subjects on the test."

"doing sample problems really helps"

"group studying"

"cute girl that doesn't know physics and just wants to hot tub does NOT help me study"

"What helped me tremendously was taking advantage of your office hours to ensure that I fully understood the concepts so that I could study effectively."

"coffee."

"Re-doing the homework and quizzes is definitely the most helpful for me."

"Drink Green Tea; no sugar no additives; helps you concentrate."

"P-Dogg's blog! Thank god for this!"

"Getting an understanding of the overall specific topic helps a great deal to understand how to use the formulas."

"studying with __________"

"Redoing the homework problems really helps me to study."

"practice problems"

"procrastinating does not help, studying does help! =P"

"Having a friend that is a physics major"

"i really like your blog when you write things out step by step it really helps"

"Don't get senioritis and focus on what you are doing"

"doing flachcard questions and reworking the homework problems based around short answer and worked out problems on the study guide"

"It's easy to get overwhelmed with the amount of information we have to sort out before we come to take the test. My advice is to not get narrow-minded and keep a brief study on all the subjects"

Online reading assignment question: confusing Midterm 2 physics topics

Physics 205A Reading Assignment 24, fall semester 2011
Cuesta College, San Luis Obispo, CA

111127-Phys205A-Midterm2-confusing
http://www.flickr.com/photos/waiferx/6415132437/
Originally uploaded by Waifer X

Wordle.net tag cloud for confusing topics covered in Midterm 2, generated by responses from Physics 205A students at Cuesta College, San Luis Obispo, CA (www.wordle.net/show/wrdl/4480072/Untitled).

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.

List at least three words describing confusing subjects covered in class (up through this midterm). (Graded for completion.)

[Responses have been edited to consolidate related common subjects.]

Student responses
Sections 70854, 70855
leverarms, buoyancy, torque
flow, inertia, gravity, flow
fluids, SHM, waves
strings waves density
physics physics physics
torque, buoyancy, flow, leverarms, rotations
buoyancy, fluids, pressure
leverarms
formulas, collisions, inertia
energy density conservation, SHM, rotations, energy
everything
everything
studyguides flashcardquestions
buoyancy, momentum, leverarms
collisions, formulas
buoyancy, buoyancy, buoyancy
torque leverarms
fluids, waves, buoyancy
fluids, buoyancy, energy conservation
buoyancy, torque, energy conservation
difficult, unrelenting, complex
Zerg torque conservation
buoyancy impulse pendulum
impulse momentum, collisions, density
buoyancy, torque, flow
work, energy conservation, torque
everything, everything, ahhh :(
pressure, fluid flow, pressure
friction friction friction
energy, buoyancy, momentum
collisions
impulse momentum, buoyancy
buoyancy stress strain
statics, momentum, stress strain
density, buoyancy, Zerg
forces, leverarms, torque
leverarms, torque, friction collisions
stress strain energy rotations inertia
difficult confusing hard
rotations, expansion, pressure
standingwaves, momentum, conservation, fluids, flow
pressure, buoyancy, friction
waves frequency


Describe your most confusing subject, and briefly explain why this subject confused you. (Graded for completion.)

The following are all of the student responses to this question, verbatim and unedited.
"Torque because it doesn't make sense to me."

"inertia, confusing"

"Fluids. It was a very broad chapter and I didn't master any part of it very well. The equations and math confuse me."

"waves, its a very odd concept for me to grasp"

"word problems"

"torque. too many weird values and parts- what the heck is a lever arm? what is an r perp? why does the T for torque look like it is sitting down?"

"Buoyancy was difficult to understand probably because I missed the lectures."

"Drawing lever arms, and knowing which lines are which."

"Trying to remember how to apply all of the different formulas is difficult for me."

"Torque because I'm still confused on determining forces and magnitude acting on the objects."

"torques"

"physics is confusion"

"Uelas and Krot"

"wave nature because i have no time the past two weeks:("

"Momentum is the most confusing subject to me on this upcoming midterm because the questions regarding momentum always are the hardest to decipher."

"I understand most of it, but it takes to long to solve a problem in a timed test setting so I need to practice more."

"Lever arms are still very confusing for me because I always seem to miss one step."

"For whatever reason I've always had more trouble with static fluids than dynamic fluids. But both subjects can be confusing at times."

"fluid, don't even know how to start it, and for other problems just sometimes don't know what is 0 and know what cancel out"

"Buoyancy and Perfectly Inelastic collisions. Instead of going over the basic concepts with flashcard questions for most of the time in class, I believe that we should do more problems in class because when we do problems we learn the basic concepts as well."

"Standing waves are most confusing because i'm having trouble comprehending resonant frequencies."

"The problems that are more complicated (like 7.43) usually mess my up. anything beyond a 'plug and chug' usually takes allot of practice for me to make sure I dont get hung up on anything. As for the zerg, they're just jerks."

"I guess i was having trouble with drawing the force diagrams accurately for these problems"

"collisions and energy conservation was the most confusing."

"buoyancy, i didnt learn it ever"

"While I feel like I understand the concept of torque, sometimes I have trouble finding r perp correctly especially when you have angles that require you to use sin, cos, tan to complete the problem."

"lever arms."

"Pressure, I just didn't get enough explanation of the equations"

"Fluid Physics - I don't know; that whole 'buoyancy' thing still irks me."

"bouyant forces, it is confusing because i haven't spent the necessary time to cover the material like i would like to."

"The problem we went over in class 7.44, WHAT THE HELLLLLLLL (P)"

"lever arms, i cant ever draw the line of motion"

"Nothing!"

"motionless, things without motion does not make sense"

"Energy conservation, mostly because we did not use it as much."

"Torques, I get really frustrated with the right hand rule."

"friction with perfectly elastic situations."

"Kinetic rotational inertia was difficult because my algebra is weak and i have trouble moving around mathematical symbols on either side of the equation such."

"Waves because there are a lot variables"

"my main problem is all circluar motion and rotational stuff because I have a hard time calculating it"

"I still can't grasp my mind around how a object/material will resonate at a certain frequency."

"bouyancy is kind of difficult to understand at first but when it is understood it is more interesting than hard"

"The most confusing part is remembering what all the variables are used for what and what their SI units are."

Online reading assignment question: interesting Midterm 2 physics topics

Physics 205A Reading Assignment 24, fall semester 2011
Cuesta College, San Luis Obispo, CA

111127-Phys205A-Midterm2-interesting
http://www.flickr.com/photos/waiferx/6415132221/
Originally uploaded by Waifer X

Wordle.net tag cloud for interesting topics covered in Midterm 2, generated by responses from Physics 205A students at Cuesta College, San Luis Obispo, CA (http://www.wordle.net/show/wrdl/4480066/Untitled).

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.

List at least three words describing interesting subjects covered in class (up through this midterm). (Graded for completion.)

[Responses have been edited to consolidate related common subjects.]

Student responses
Sections 70854, 70855
collisions, momentum, impulse
momentum, collisions, pressure
torque, stress, strain, pendulum
pressure, strings, stress, strain
physics physics physics
sound, waves, collisions
momentum, torque, buoyancy
density
torque, buoyancy, conservation
buoyancy, collisions, momentum
momentum, torque, inertia
nothing
pendulum, massspring
buoyancy, momentum, leverarms
energy, torque, Eureka!
torque, momentum, collisions
collisions, buoyancy, momentum
fluids flow, sound, stress strain
equations, fluids, work
torque, energy, conservation, momentum
fascinating, informative, simple
torque momentum, conservation work
stress, strain, forces leverarms
collisions, buoyancy, torque
sound, SHM, tension
buoyancy, momentum, conservation, sound
leverarms, buoyancy, momentum
torque, waves, collisions
resonance bridges
impulse, momentum, forces, collisions
buoyancy forces, torque
centerofgravity, torque, stress, strain
buoyancy, conservation, momentum
collisions, statics, collisions
fluids, flow, density, paranormalactivity
impulse, collisions, energy
collisions, impulse, momentum, leverarms
standingwaves sound buoyancy
hard harder hardest
sound, standingwaves, torque
fluids, flow, buoyancy, SHM
buoyancy, torque, momentum
buoyancy, energy pressure


Describe your most interesting subject, and briefly explain why this subject interested you. (Graded for completion.)

The following are all of the student responses to this question, verbatim and unedited.
"Perfectly inelastic collision because it's fun to watch things crash and calculate things about it"

"densities, easy to do"

"Torques, because it's the topic I understood most conceptually and mathmatically."

"momentum conservation"

"sound waves, because its something we can't always see"

"Ch 12- speed of sound was most interesting because it was most applicable to my life. I have played instruments before (wind and string) so it is cool to see how air flows and frequency changes."

"Momentum, Collisions, Torque"

"Using relative buoyancy to calculate the density of an object, because it was a fun lab."

"Torque. I liked it because it is fairly simple to get the hang of and it's fun to see it's application in real life."

"Pressure and buoyancy are most interesting because they directly supplement material I teach at my job."

"momentum, because it describes how to objects interact with ea. other on impact"

"nothing"

"definitely wavelengths and frequencys"

"bouyancy cuz it has a different application that the word"

"The most interesting subject to me that will be covered in this midterm would be stress and strain, you pick one and you'll most likely get both, anyways this subjects interests me the most due to common relevancy it has to everyday life."

"Torque, I understand it well. Plus its helpful information!"

"I really like buoyant forces because the concept was easy for me to understand."

"tress/Strain. I recently took ENGR 252. That is the basis of the class and has always interested me."

"energy conservation"

"Torque."

"Torque, because i find it easy to calculate. It just makes sense."

"there just the most important topics"

"I think elastic forces would be cool to see on a larger scale"

"buoyant forces were the most interesting because they worked counterintuitively."

"harmonic motion, it is cool."

"Sound waves are my most interesting subject of this midterm. It's just really interesting to learn about how something works that is present in you life 24/7!"

"momentum because you were able to relate it to real life car crashes"

"Waves, I had never understood exactly how sound worked, and I found this a fascinating explanation of it."

"lever arms, and I'm not sure. Now when I see a bridge, I see math equations."

"collision's; since the semester started this particular subject interested me the most, no exact explanation but I enjoy this subject."

"i liked the buoyancy forces because i could apply them outside and FINALLY understand it, the lab helped a lot"

"collision/elasticity - it is easy for me"

"I like perfectly inelastic collisions"

"collisions, car crashing are interesting"

"density, because I finally discovered how hyrdrolic pistons work."

"Kinetic energy was the most interesting subject because I like they way the equations work."

"perfectly inelastic, the overall thought process of the problem is what interests me over other physic categories."

"Fundamental Frequencies because i got to learn how bridges fall apart!"

"Torque because I can apply it to working with tools"

"i enjoy real world examples like waves that we see and hear every day"

"'hydrostatic weighing' is a cool alternative method for finding weight and density"

"i like how torque is determined with the lever arms and forces and the fact that if you have a bigger lever arm less force is required to obtain the certain amount of torque"

"Conservation of energy is very interesting to me because the fact that energy is never created or destroyed."

Astronomy midterm question: blue supergiants just as bright as red supergiants?

Astronomy 210 Midterm 2, fall semester 2011
Cuesta College, San Luis Obispo, CA

An astronomy question on an online discussion board(*) was asked and answered:
Pd...: Is it possible that a blue supergiant can be as bright as a red supergiant, (assuming they are the same distance from Earth)?
per..gogy: Technically the blue supergiant would be the brighter one. Blue stars are more luminous than red stars...
Discuss whether or not if this answer is correct, and how you know this. Explain using Wien's law, the Stefan-Boltzmann law and/or an H-R diagram.

*Source: http://answers.yahoo.com/question/index?qid=20110602185220AATh4tm.

Solution and grading rubric:
  • p = 20/20:
    Correct. Wien's law: blue stars are hotter, and are located on the left side of an H-R diagram, while red stars are cooler, and are located on the right side. Uses Stefan-Boltzmann law and/or interprets H-R diagram to show that either (a) blue supergiants and red supergiants can have the same size, such that the blue supergiants (being hotter) are more luminous; or (b) blue supergiants and red supergiants can have the same luminosity, but the blue supergiants (being hotter) are smaller in size.
  • r = 16/20:
    Nearly correct (explanation weak, unclear or only nearly complete); includes extraneous/tangential information; or has minor errors.
  • t = 12/20:
    Contains right ideas, but discussion is unclear/incomplete or contains major errors.
  • v = 8/20:
    Limited relevant discussion of supporting evidence of at least some merit, but in an inconsistent or unclear manner. At least attempts to use Wien's law, H-R diagram and/or the Stefan-Boltzman law.
  • x = 4/20:
    Implementation/application of ideas, but credit given for effort rather than merit. Discussion not based on Wien's law, H-R diagram and/or the Stefan-Boltzman law.
  • y = 2/20:
    Irrelevant discussion/effectively blank.
  • z = 0/20:
    Blank.
Grading distribution:Section 70160
Exam code: midterm02n1cT
p: 13 students
r: 6 students
t: 6 students
v: 3 students
x: 0 students
y: 0 students
z: 0 students

A sample "p" response (from student 8386), discussing how the blue supergiant while hotter, would be smaller than the red supergiant in order to have the same luminosity:
Another sample "p" response (from student 1027) instead arguing that a blue supergiant will be brighter than a red supergiant, assuming that they are the same size:

20111126

Astronomy midterm question: red dwarf vs. massive main-sequence star metallicity

Astronomy 210 Midterm 2, fall semester 2011
Cuesta College, San Luis Obispo, CA

An astronomy question on an online discussion board[*] was asked and answered:
Pd: Which star today would have more metals: a red dwarf or a massive main-sequence star?
qp: I'm guessing a massive main-sequence star; because a red dwarf is likely very old...
Discuss whether or not if this answer is correct, and how you know this. Explain using the properties and evolution of stars.

[*] answers.yahoo.com/question/index?qid=20110601124741AA76NMC.

Solution and grading rubric:
  • p:
    Correct. Understands that:
    1. older stars are metal-poor having formed from essentially just hydrogen, while newer stars are metal-rich, having formed from hydrogen enriched with metals produced by previous generation stars;
    2. red dwarfs take a long time to become main sequence stars, such that they had to have started forming a long time ago, are thus are metal-poor, while massive stars take a short time to form, such that they formed recently, and thus are metal-rich.
  • r:
    Nearly correct (explanation weak, unclear or only nearly complete); includes extraneous/tangential information; or has minor errors. One of the two points (1)-(2) is correct, other is problematic.
  • t:
    Contains right ideas, but discussion is unclear/incomplete or contains major errors. Only one of the two points (1)-(2) correct, other is missing, or both are problematic.
  • v:
    Limited relevant discussion of supporting evidence of at least some merit, but in an inconsistent or unclear manner. Garbled discussion of properties and evolution of stars, such as breaking down of metals; masses and evolution rates.
  • x:
    Implementation/application of ideas, but credit given for effort rather than merit.
  • y:
    Irrelevant discussion/effectively blank.
  • z:
    Blank.
Grading distribution:
Section 70158
Exam code: midterm02s3Ar
p: 9 students
r: 3 students
t: 14 students
v: 8 students
x: 0 students
y: 0 students
z: 0 students

Section 70160
Exam code: midterm02n1cT
p: 9 students
r: 3 students
t: 9 students
v: 6 students
x: 1 student
y: 0 students
z: 0 students

A sample "p" response (from student 2541):
Another sample "p" response (from student 1863), using a "House Party" analogy:
Yet another sample "p" response (from student 1985), lavishly illustrated:
A sample "v" response (from student 0628), where older stars would have had more time to absorb metals than recent stars:
Another sample "v" response (from student 1226), where older stars have more time to break down metals:
Yet another sample "v" response (from student 1559), where older stars have more time to fuse metals by breaking them down:

20111125

Astronomy midterm question: you at where big bang started?

Astronomy 210 Midterm 2, fall semester 2011
Cuesta College, San Luis Obispo, CA

[20 points.] An astronomy question on an online discussion board[*] was asked and answered:
sai: We know that [the] big bang created everything we know today, but if it formed the universe where did the big bang take place?!
Dude: Right where [you] are standing.
Discuss why this answer is correct, and how you know this. Explain using observations and evidence related to the Hubble law.

[*]Source: http://answers.yahoo.com/question/index?qid=20100926113402AAQcp5I.

Solution and grading rubric:
  • p = 20/20:
    Correct. Understands that (a) Hubble's law is that the recession velocity of galaxies is proportional to distance (greater redshift of absorption lines for distant galaxies compared to nearby galaxies), corresponding to the expansion of space between galaxies, and (b) extrapolating time backwards means that the distance between everything was zero, thus any location can be said to be where the big bang took place (or may instead argue for no unique center of expansion for expanding-space-between-galaxies universe).
  • r = 16/20:
    Nearly correct (explanation weak, unclear or only nearly complete); includes extraneous/tangential information; or has minor errors. One of the two points (a)-(b) is correct, other is problematic.
  • t = 12/20:
    Contains right ideas, but discussion is unclear/incomplete or contains major errors. Only one of the two points (a)-(b) correct, other is missing, or both are problematic.
  • v = 8/20:
    Limited relevant discussion of supporting evidence of at least some merit, but in an inconsistent or unclear manner. Discussion based on evidence of the earlier stages in the history of the universe, with little or no substantive discussion of Hubble's law, such as everything was created by the big bang, therefore everything can be said to be where the big bang took place.
  • x = 4/20:
    Implementation/application of ideas, but credit given for effort rather than merit.
  • y = 2/20:
    Irrelevant discussion/effectively blank.
  • z = 0/20:
    Blank.
Grading distribution:
Section 70158
Exam code: midterm02s3Ar
p: 4 students
r: 11 students
t: 9 students
v: 7 students
x: 3 students
y: 0 students
z: 0 students

Section 70160
Exam code: midterm02n1cT
p: 7 students
r: 7 students
t: 7 students
v: 4 students
x: 2 students
y: 1 student
z: 0 students

A sample "p" response (from student 1027):
A sample "v" response (from student 1177):
Another sample "v" response (from student 8436), still showing the astronomy love:

20111124

Physics quiz question: stress, strain on brick

Physics 205A Quiz 6, fall semester 2011
Cuesta College, San Luis Obispo, CA

Cf. Giambattista/Richardson/Richardson, Physics, 2/e, Conceptual Question 10.4

A load is to be supported by a brick placed in either of two orientations. To compress by 0.1 mm, __________ will require a greater force.
(A) brick (A).
(B) brick (B).
(C) (There is a tie.)
(D) (Not enough information is given.)

Correct answer (highlight to unhide): (A)

Hooke's law is given by:

(F/A) = Y·(∆L/L),

or:

F = Y·∆L·(A/L),

where Y and ∆L is the same for both bricks. The brick with orientation (A) has a larger cross-sectional area A that force is applied to, and also a shorter L along the direction that force is applied, such that it will require more force than the brick with orientation (B).

Sections 70854, 70855
Exam code: quiz06w4VE
(A) : 39 students
(B) : 8 students
(C) : 3 students
(D) : 2 students

Success level: 74%
Discrimination index (Aubrecht & Aubrecht, 1983): 0.22

20111123

Physics quiz question: mass-spring potential energy

Physics 205A Quiz 6, fall semester 2011
Cuesta College, San Luis Obispo, CA

Cf. Giambattista/Richardson/Richardson, Physics, 2/e, Multiple-Choice Question 10.13

A 0.75 kg mass attached to a horizontal spring has a 4.0 s period of oscillation. Neglect friction and drag. The velocity versus time graph for this mass-spring system is shown at right. What is the earliest time that the system will have its maximum elastic potential energy?
(A) 0 s.
(B) 1 s.
(C) 2 s.
(D) 3 s.

Correct answer: (B)

The elastic potential energy Uelas of the mass-spring system will be at a maximum when the translational kinetic energy Ktr is zero, which occurs at t = 1 s, which is the earliest time when the velocity v is zero.

Sections 70854, 70855
Exam code: quiz06w4VE
(A) : 16 students
(B) : 25 students
(C) : 11 students
(D) : 1 student

Success level: 47%
Discrimination index (Aubrecht & Aubrecht, 1983): 0.68

20111122

Physics quiz question: increasing frequency of wave source

Physics 205A Quiz 6, fall semester 2011
Cuesta College, San Luis Obispo, CA

Cf. Giambattista/Richardson/Richardson, Physics, 2/e, Multiple-Choice Questions 11.5, 11.6

A periodic wave has a frequency and wavelength of 125 Hz and 0.60 m, respectively. If the frequency of the wave source is increased, the __________ would increase.
(A) wave speed.
(B) wavelength.
(C) (Both of the above choices.)
(D) (Neither of above choices.)

Correct answer: (D)

Wave speed v depends on the properties of the medium. Frequency f depends on the properties of the source. These two parameters can be varied independently of each other.

The wavelength λ is the parameter dependent on both of the independent parameters:

λ = v/f,

such that increasing the frequency f of a wave source will not affect the wave speed v, but will cause the wavelength λ to decrease.

Response (A) is incorrectly interpreting the mathematically correct statement:

v = λ·f,

to mean that the wave speed v depends on wavelength λ and frequency f.

Sections 70854, 70855
Exam code: quiz06w4VE
(A) : 26 students
(B) : 4 students
(C) : 0 students
(D) : 23 students

Success level: 43%
Discrimination index (Aubrecht & Aubrecht, 1983): 0.46

20111121

Physics quiz question: frequency of standing wave on a string

Physics 205A Quiz 6, fall semester 2011
Cuesta College, San Luis Obispo, CA

Cf. Giambattista/Richardson/Richardson, Physics, 2/e, Conceptual Question 11.4, Multiple-Choice Question 11.5

A viola's A-string[*],[**] has a length of 0.37 m and is stretched to a tension of 53 N. It vibrates at a fundamental frequency of 440 Hz. In order to increase the fundamental frequency of this viola string, which of the following should be done?
(A) Press a finger on the string, such that a shorter length of it vibrates.
(B) Increase the tension of the string.
(C) (Both of the above choices.)
(D) (Neither of the above choices.)

[*] theviolaworkshop.com/page16.html.
[**] gamutmusic.squarespace.com/viola-tensions/.

Correct answer (highlight to unhide): (C)

The fundamental frequency of a standing wave on a string is given by:

f1 = (1/(2·L))·sqrt(F/(m/L)),

such that either decreasing the length L of the string, or increasing the tension F of the string would both result in an increase in f1.

Sections 70854, 70855
Exam code: quiz06w4VE
(A) : 13 students
(B) : 13 students
(C) : 26 students
(D) : 2 students

Success level: 49%
Discrimination index (Aubrecht & Aubrecht, 1983): 0.73

20111120

Physics quiz archive: simple harmonic motion, waves

Physics 205A Quiz 6, fall semester 2011
Cuesta College, San Luis Obispo, CA
Sections 70854, 70855, version 1


Sections 70854, 70855 results
Exam code: quiz06w4VE
 0- 6 : **  [low = 6]
7-12 : ********
13-18 : ***************
19-24 : ******************** [mean = 19.2 +/- 5.2]
25-30 : ******** [high = 30]

20111119

Overheard: recursive learning about stars

Astronomy 210, fall semester 2011
Cuesta College, San Luis Obispo, CA

(Overheard at a review session just before midterm on the sun/stars/Milky Way/cosmology.)

Instructor: "Just think: you're learning about stars that died...to make the atoms...that made you...so you could learn...about the stars."

Students: (Beat.) "Whoa."

Instructor: "Yeah. Whoa."

20111118

Astronomy current events question: Phobos-Grunt mission

Astronomy 210L, fall semester 2011
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!)
Jonathan Amos, "Asteroid Lutetia May Have Core of Hot Melted Metal," November 9, 2011
http://www.bbc.co.uk/news/science-environment-15631472
The Russian Space Agency Phobos-Grunt spacecraft, which is experiencing technical problems, was intended to travel to Mars to:
(A) bring back a sample from one of its moons.
(B) burrow underground to search for water.
(C) produce fuel for future space missions.
(D) search for the defunct NASA Spirit rover.
(E) map the "face on Mars" with high-resolution radar.

Correct answer: (D)

Student responses
Sections 70178, 70186, 70200
(A) : 38 students
(B) : 8 students
(C) : 0 students
(D) : 3 students
(E) : 7 students

Astronomy current events question: asteroid 21 Lutetia

Astronomy 210L, fall semester 2011
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!)
Charles Q. Choi, "Asteroid Lutetia May Have Core of Hot Melted Metal," October 27, 2011
http://www.msnbc.msn.com/id/45065506/ns/technology_and_science-space#.TsdVq4BW4lZ
The __________ of asteroid 21 Lutetia measured by the European Space Agency Rosetta spacecraft may be evidence that the asteroid has a molten metal core.
(A) reflectivity.
(B) crater density.
(C) infrared emissions.
(D) density.
(E) roundness.

Correct answer: (D)

Student responses
Sections 70178, 70186, 70200
(A) : 0 students
(B) : 6 students
(C) : 13 students
(D) : 37 students
(E) : 0 students

Astronomy current events question: 2011 Leonid meteor shower

Astronomy 210L, fall semester 2011
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!)
Bill Andrews, "Get Ready for the 2011 Leonid Meteor Shower," November 8, 2011
http://astronomy.com/News-Observing/News/2011/11/Get%20ready%20for%20the%202011%20Leonid%20meteor%20shower.aspx
The Leonid meteor shower that peaks on the morning of November 18 will be expected to be muted this year because of:
(A) the end of daylight saving time.
(B) a partial lunar eclipse.
(C) intense northern light activity.
(D) light from the moon.
(E) asteroid 2005 YU55 passing by Earth earlier this month.

Correct answer: (D)

Student responses
Sections 70178, 70186, 70200
(A) : 1 student
(B) : 4 students
(C) : 3 students
(D) : 37 students
(E) : 11 students

Online reading assignment question: keep, quit, start

Astronomy 210 Keep-Quit-Start Reading Assignment, fall semester 2011
Cuesta College, San Luis Obispo, CA

111116-astr210-keep
http://www.flickr.com/photos/waiferx/6350653663/
Originally uploaded by Waifer X

Wordle.net tag cloud for "keep" resolutions generated by responses from Astronomy 210 students at Cuesta College, San Luis Obispo, CA, fall semester 2011 (www.wordle.net/show/wrdl/4424300/Untitled).


111116-astr210-quit
http://www.flickr.com/photos/waiferx/6351397434/
Originally uploaded by Waifer X

Wordle.net tag cloud for "quit" resolutions generated by responses from Astronomy 210 students at Cuesta College, San Luis Obispo, CA, fall semester 2011 (www.wordle.net/show/wrdl/4424360/Untitled).


111116-astr210-start
http://www.flickr.com/photos/waiferx/6351397506/
Originally uploaded by Waifer X

Wordle.net tag cloud for "start" resolutions generated by responses from Astronomy 210 students at Cuesta College, San Luis Obispo, CA, fall semester 2011 (www.wordle.net/show/wrdl/4424146/Untitled).


Students were asked to answer a "keep-quit-start" online reflection (hosted by SurveyMonkey.com) on their studying strategies/pitfalls (Mubayiwa, 2009).
Enter a word or brief phrase that describes what you intend to keep doing to study for this class. Explain your answer to the above question (what you intend to keep doing to study for this class).

Enter a word or brief phrase that describes what you intend to quit doing to study for this class. Explain your answer to the above question (what you intend to quit doing to study for this class).

Enter a word or brief phrase that describes what you intend to start doing to study for this class. Explain your answer to the above question (what you intend to start doing to study for this class).
[Word tags have been edited to consolidate related common subjects; student explanations are verbatim.]

Student responses
Sections 70158, 70160

Keep word tags:
effort
At the end of the day, all you can truly ask of someone is to try their best.

flashcardquestions ("peer instruction," "think-pair-share")
After not using the flashcard packets, I realized that studying them and filling them out really does improve my understanding of the subject.
I mean to keep printing out the Flash Card Notes to study them because it helps with Quizzes.
Read these through is extra review.
it really helps to study them, to help rememer what we learned in class.
Going over old quizzes and flashcard questions helps me review the material
By printing out the flashcard questions it allows me to keep on track while reading, and write down correct answers that we go over in class. This then makes it less confusing when I am trying to go back a few days and study.
Write down questions and answers from class
They give A great forecast for quizzes

gotoclass
I've found sometimes just reading from the textbook maybe dry and somewhat vague. So coming to lecture definitely helps to get a better grasp of the material.
I will keep attending class because that is where you learn everything.
Lecture helps me to better understand what I read in the book, as well as information i need clarified.
I'll keep attending class
missing a lecture sucks, cause then you have to read and be totally confused.

notes
good lecture notes help alot when studying for tests.

participate
Participating in flashcard questions and group work is essential to understanding concepts.

payattention
just pay good attention to the lecture

practiceexams
When I study old quizzes it helps me understand things better and helps me know what I should study for, for the next quiz.
Before each quiz and midterm, I will continue to review the practice quizzes to better prepare myself and be more familiar with the types of questions.

read
reading the chapters of the book
I have this really bad habit of never touching my textbooks. I should really get over it.
I am forcing myself to ingrain the habit to do all post labs, prereads, and other online assignments on one day before the start of the week.

review
In order to do well on the quizzes and midterms, I know that I need to review the information we go over every week, and study the sample questions we do in class in order to better understand the material and do well on the tests.

study
I intend to KEEP studying hard the several days before quizzes, midterm 2, and the final.
I need to keep studying, because studying is important.
I will keep reading the book no matter how hard.
I am taking notes, printing out all the flashcard questions, and continuing to study.
What else do I have to say? Always study and be prepared for any assignment or test.
It is important to get a good grade.
I read the book and I study for the midterm and read flashcard questions.
Study, and go to class
I need to study the material a little bit more to keep succeeding

studygroups
I study with another classmate and it helps quite a bit on the quizes.


Quit word tags:
cramming
Get over loaded before class

distractions
Facebook is pretty distracting especially when doing homework assignments on the computer.

doodling
I only did this once, but then I was completely confused next lecture.
getting distracted during lecture by doodling

gettingsick
i unfortunately had to walk out of class because i was coughing up a lung last session. I have been taking my Vitamin C and feel confident that I am over my cold.

lackofcaffeine
I always come straight to class after long work days, and I really need to drink more caffeine and have a more balanced meal prior to.

laziness
not be lazy and just blow off the reading assigments they're easy points

leavingearly
Staying in class for both parts of lecture is important.
I'm going to stay the whole class

missclass
i would like to go to class to get the particpation points and get the info
I will not miss any classes or homework
Whenever I miss class I miss something important.
missing a lecture sucks, cause then you have to read and be totally confused.
Not attending due to its length of class and terrifying time of class

noclue
I have no idea

nothing
There is nothing that i intend to quit doing in order to succeed in this class
If I quit, I fail.

notstudying
I will stop not studying so i do better on tests.

procrastination
Usually after class I won't look at what we went over with the idea that I'll study it later before the quiz. If I want to fully understand the material I have to review it more frequently.
When I study for a quiz at the last minute I end up being really tired for the quiz or exam and end up not doing my best.
I intend to QUIT procrastinating and study even sooner so that Sunday studying isn't so intense. It hasn't hurt my performance, but it would be less stressful and allow more time for my brain to absorb all the information.
I tend to procrastinate in classes that don't assign daily homework or papers. I intend to spend more time studying for astronomy quizzes and exams.
My worst quality!
I tend to procrastinate in every class. I should change that... but I'll probably put off breaking that habit. :[
I keep waiting until the last second to do surveys and end up forgetting. I need to do them on Thursdays or something.
Stop procrastinating when it comes to studying for quizzes and midterms.
I need to just do the reading and not wait until the night before.
i have a habit of it, i need to motivate myself to get things done earlier
I often wait until Wednesday night to do homework and study. I will try and work on Astronomy earlier in the week and more frequently
I need to start reading chapters on time

quitting
I got to quit quitting.

skippingmeals
I don't usually skip out on meals, but I like to at least have some amount of nutritious food energizing my body.

slacking
now that i have more time to focus on school, i intend to study way more for this class.
I haven't been keeping up with studying for this class (blame College Algebra for that P-Dog).


Start word tags:
ask
Most people wont ask questions in class. If I don't understand a concept I'll start raising my hand more too better understand what's going on.

caffeinate
I need more of it.

examples
I am going to analyze the examples provided in the textbook that relate to the subject(s) I need to study.

flashcardquestions ("peer instruction," "think-pair-share")
Start reading flashcard questions to see what will be on the test.
I need to do more of the flashcards
Printing out Flash Cards before class instead of after
Because a lot of the quizes and tests are just the same questions, but also since the packets cover just about everything we need to know regardless. Or at least hit the main points.
I did the flash card questions for the last midterm to help study and they helped a ton. so im gonna start dion them again.
Sending in my flash card answers so I know I am studying correctly

focus
Gotta focus on studying and reviewing as much as possible for the class; going over material and reviewing the study questions.

fullspeedahead
Don't worry so much and keep pushing for success

notes
I should probably take more notes during lecture.
take better notes during lecture
By writing group work questions down I will have more reference questions and more to study for quizzes and midterms
Write more detailed notes from lectures
A well maintained note book can make or break a grade, and i plan to always improve my note taking skills

practiceexams
These practice quizzes are really helpful because it helps you identify what you need to know for the quiz.

read
I intend to start going through the book to help me understand things better when I get lost or confused.
Reading the book is important.
From lecture and also reading the textbook it makes thing become more clear and you're able to understand the material a little better.
I will start to read the book more.
I wish I could but I can't.

research
I should look up articles relating to the questions on the survey reading, not just to get the answers to the questions, but know why the evidence supports it.

starting
Missing the easy homework points has lowered my grade, I need to start to consistently remember to complete the homework.
i need to stop procrastinating.
I need to start studying for quizzes and tests sooner in order to remember all the information

study
need to study more and pay better attention to what im studying
I intend to allocate more time to studying for this class since I know that I have neglected it compared to studying for my other classes.
Giving myself more time to study
As it gets closer to end of the semester, I need to bump up my studying to ensure that I get the grade that I want.
I will study harder for the next midterm
Study group for midterm
Going over flashcard question, reading the book for overview, and making sure I know the material beyond what I merely remember from class.

studygroup
I think it would be helpful to study with a classmate and practice quizzing each other. I think it would make studying more fun and effective.
Getting together with other students might help.


Previous posts:
  • Online reading assignment question: keep, quit, start (Physics 205A, fall semester, 2011).
  • Online reading assignment question: keep, quit, start (Astronomy 210, spring semester, 2011).
  • Online reading assignment question: keep, quit, start (Astronomy 210, fall semester, 2010).
  • 20111117

    Astronomy quiz question: monolithic collapse model

    Astronomy 210 Quiz 6, fall semester 2011
    Cuesta College, San Luis Obispo, CA

    According to the monolithic collapse model, there should be no young stars in globular clusters because:
    (A) metal-rich stars in the halo have already become metal-poor stars.
    (B) there are no metals left in the halo.
    (C) dark matter in the halo prevents new stars from forming.
    (D) interstellar hydrogen in the halo moved into the disk.

    Correct answer: (D).

    Since the distribution of interstellar hydrogen in the Milky Way has flattened from spherical to disk-shaped, new star formation occurs only in the disk, and not in the halo, where the first generation stars of the globular clusters are located.

    Section 70160
    Exam code: quiz06n4Nd
    (A) : 11 students
    (B) : 4 students
    (C) : 2 students
    (D) : 9 students

    Success level: 40% (including partial credit for multiple-choice)
    Discrimination index (Aubrecht & Aubrecht, 1983): 0.63

    Astronomy quiz question: globular star clusters

    Astronomy 210 Quiz 6, fall semester 2011
    Cuesta College, San Luis Obispo, CA

    The locations of globular star clusters provide evidence for:
    (A) dark matter in the halo.
    (B) self-sustaining star formation.
    (C) the Milky Way's spiral arm structure.
    (D) the location of the Milky Way's center.

    Correct answer: (D).

    The distribution of globular clusters in the halo, above and below the disk, is used to locate the center of the Milky Way.

    Section 70158
    Exam code: quiz06pOp1
    (A) : 2 students
    (B) : 1 students
    (C) : 6 students
    (D) : 23 students

    Success level: 75% (including partial credit for multiple-choice)
    Discrimination index (Aubrecht & Aubrecht, 1983): 0.56

    Section 70160
    Exam code: quiz06n4Nd
    (A) : 1 student
    (B) : 1 student
    (C) : 6 students
    (D) : 9 students

    Success level: 61% (including partial credit for multiple-choice)
    Discrimination index (Aubrecht & Aubrecht, 1983): 0.49

    Astronomy quiz question: spiral arm tracers

    Astronomy 210 Quiz 6, fall semester 2011
    Cuesta College, San Luis Obispo, CA

    Spiral arms can be traced through the sun's neighborhood by locating the positions of spiral tracers such as:
    (A) Cepheid variable stars.
    (B) globular clusters.
    (C) type Ia and type II supernovae.
    (D) massive stars.

    Correct answer: (D).

    Massive stars are luminous and short-lived, so they only be located near where they were born from a spiral arm density wave. Cepheid variable stars are used to determine the distances to globular clusters in the halo of the Milky Way, and the distribution of globular clusters is used to locate the center of the Milky Way. Observations of type Ia and type II are used to determine the distances to other galaxies.

    Section 70158
    Exam code: quiz06pOp1
    (A) : 9 students
    (B) : 11 students
    (C) : 4 students
    (D) : 7 students
    (No response: 1 student)

    Success level: 27% (including partial credit for multiple-choice)
    Discrimination index (Aubrecht & Aubrecht, 1983): -0.13

    20111116

    Astronomy quiz archive: Milky Way, cosmology

    Astronomy 210 Quiz 6, fall semester 2011
    Cuesta College, San Luis Obispo, CA

    Section 70158, version 1
    Exam code: quiz06pOp1

    Section 70158
    Quiz 6 results (max score = 40):
    0- 8.0 : * [low = 7.5]
    8.5-16.0 : ****
    16.5-24.0 : ************** [mean = 22.8 +/- 6.6]
    24.5-32.0 : **********
    32.5-40.0 : *** [high = 36.5]

    Astronomy quiz archive: Milky Way, cosmology

    Astronomy 210 Quiz 6, fall semester 2011
    Cuesta College, San Luis Obispo, CA

    Section 70160, version 1
    Exam code: quiz06n4Nd

    Section 70160
    Quiz 6 results (max score = 40):
    0- 8.0 : * [low = 6.0]
    8.5-16.0 : **
    16.5-24.0 : ****
    24.5-32.0 : ********** [mean = 27.4 +/- 9.0]
    32.5-40.0 : ********* [high = 40.0]