Physics quiz question: equivalent resistance of circuit

Physics 205B Quiz 4, spring semester 2011
Cuesta College, San Luis Obispo, CA

Cf. Giambattista/Richardson/Richardson, Physics, 2/e, Comprehensive Problem 18.65(a).

An ideal 16.0 V emf source is connected to a 15 Ω resistor and two 2.2 Ω light bulbs, as shown at right. The equivalent resistance of this circuit is:
(A) 1.0 Ω.
(B) 2.0 Ω.
(C) 4.1 Ω.
(D) 6.5 Ω.

Correct answer: (C)

Light bulb 1 and the 15 Ω resistor are in parallel with each other, and so their equivalent resistance is the reciprocal of the sum of their reciprocals:

R_(bulb_1,_15 Ω) = ((2.2 Ω)^-1 + (15 Ω)^-1)^-1 = 1.9 Ω,

And this interim equivalent resistor is in series with light bulb 2, such that the equivalent resistance of the circuit is the summation:

R_(circuit) = 1.9 Ω + 2.2 Ω = 4.1 Ω.

Response (A) is the result of all three circuit elements in parallel with each other; response (B) is where light bulb 1 and the 15 Ω resistor are in series with each other, then combined in parallel with light bulb 2; response (D) is the average resistance of all three circuit elements.

Student responses
Section 30822
Exam code: quiz05t4Uo
(A) : 2 students
(B) : 2 students
(C) : 4 students
(D) : 0 students

Success level: 50%
Discrimination index (Aubrecht & Aubrecht, 1983): 0.50

Physics quiz archive: capacitors, circuits (2)

Physics 205B Quiz 5, Spring Semester 2011
Cuesta College, San Luis Obispo, CA

Section 30882, version 1

Section 30882 results
Exam code: quiz05t4Uo

 0- 6 : 
 7-12 : **  [low = 9]
13-18 : **
19-24 : *  [mean = 20.3 +/- 7.1]
25-30 : ***    [high = 27]

Astronomy current events question: new particle or fundamental force?

Astronomy 210L, Spring 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!)

Elizabeth Landau, "Is It A New Particle, Or Just A Fluke?," April 8, 2011
http://www.cnn.com/2011/US/04/08/particle.physics.tevatron/

Fermilab scientists announced results from __________ may be evidence of a previously undiscovered particle or fundamental force.
(A) radio interference.
(B) proton and antiproton collisions.
(C) miniature black holes.
(D) dark matter samples.
(E) the Sendai earthquake.

Correct answer: (B)

Student responses
Sections 30678, 30679, 30680
(A) : 10 students
(B) : 28 students
(C) : 2 students
(D) : 8 students
(E) : 2 students

Astronomy current events question: watery comet nucleus

Astronomy 210L, Spring 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!)

Astronomy.com editors, "Two Dying Stars Reborn as One," April 6, 2011
http://astronomy.com/News-Observing/News/2011/04/Frozen%20comet%20had%20a%20watery%20past%20University%20of%20Arizona%20scientists%20find.aspx

__________ found in sample from comet 81P/Wild 2 may be evidence of liquid water in a comet.
(A) Dry ice.
(B) Water-soluble minerals.
(C) Trapped air bubbles.
(D) Radioactive particles.
(E) Primitive algae-like fossils.

Correct answer: (B)

Student responses
Sections 30678, 30679, 30680
(A) : 11 students
(B) : 28 students
(C) : 2 students
(D) : 0 students
(E) : 8 students

Astronomy current events question: merging white dwarfs

Astronomy 210L, Spring 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!)

Astronomy.com editors, "Two Dying Stars Reborn as One," April 7, 2011
http://astronomy.com/en/News-Observing/News/2011/04/Two%20dying%20stars%20reborn%20as%20one.aspx

Two white dwarfs orbiting each other will merge and become a single helium-fusing star, because:
(A) their orbital energy is being lost as gravitational waves.
(B) of perturbations caused by a passing black hole.
(C) of a nearby type II supernova.
(D) they will both expand as supergiants.
(E) their gravitational pull increases from heavy element fusion.

Correct answer: (A)

Student responses
Sections 30678, 30679, 30680
(A) : 8 students
(B) : 0 students
(C) : 2 students
(D) : 1 student
(E) : 14 students

Astronomy current events question: black hole jets

Astronomy 210L, Spring 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!)

Francis Reddy, "NASA Telescopes Join Forces to Observe Unprecedented Explosion," April 7, 2011
http://www.nasa.gov/topics/universe/features/star-disintegration.html

NASA's Swift, Hubble, and Chandra Space Telescopes are all observing __________, which may be evidence of material from a star falling into a black hole.
(A) a jet of x-ray and gamma rays.
(B) space-time distortions.
(C) rapidly flickering flashes.
(D) a growing accretion disk.
(E) hydrogen converting to dark matter.

Correct answer: (A)

Student responses
Sections 30678, 30679, 30680
(A) : 11 students
(B) : 4 students
(C) : 5 students
(D) : 2 students
(E) : 3 students

Online reading assignment question: big bang tags (pre-instruction)

Astronomy 210 Reading Assignment 11, Spring Semester 2011
Cuesta College, San Luis Obispo, CA

101117-prebigbangwordle
http://www.flickr.com/photos/waiferx/5185277783/
Originally uploaded by Waifer X

Wordle.net tag cloud for "big bang" (pre-instruction) generated by responses from Astronomy 210 students at Cuesta College, San Luis Obispo, CA, spring semester 2011 (http://www.wordle.net/show/wrdl/3423598/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.

Write down five words that describe or are associated with the "big bang." Keep word phrases together with no spaces between them (e.g., "forexample, likethis, nospaces"). (Graded for completion.)

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

Student responses
Sections 70158, 70160

beginning Hubbletime hot spacedisappearing universe
loud unexpected scary random die
theory, TVshow, notmuch, explosion, crater
beginning, universe, planets, stars, explosion
accident, theory, bang, big
big huge massive bang enormous
stars, universe, expansion, explosion, atmosphere
unsupportable, confusing, theory, TVshow, universe
theory creation beginning
zoink, boom, pow, kablam, zap
beginning, theory, universeformation, unknown, belief
cosmologicaltheory, science, space, evolution, boom
beginning, large, forever, expansion, end
stars, big, small, infinite, lightspeed, density
real, evidence, ithappened, wow, talkingsnakesarefake, real
theory, universe, birth, TVshow, creation
Sheldon Leonard Howard Penny Raj
hydrogen, helium, stars, universe, expansion
bang creation universe blackholes expansion
boom
TVshow, accepted, explosion, upsetting
boom, theory, dinosaurs, meteors, explosion
real, startoflife, explosion, startfromnothing, confusing
comingtogether, decreasing, highdensity
expansion, observation, evidence, cosmology, Hoyle
fromsomewhere o.O
cosmological universe density temperatures atom
yes yes yes yes yes
expansion, universe, stillexpanding, galaxies, theory
beginning, cosmicmicrowave, Hubbletime, antimatter
cosmic, hot, dense, galaxies, rapid
creation infinite explosion galaxies unknown
TVshow bang big explosion universe
beginning time TVshow universe sneezing
fake notreal noevidence poorlogic effectwithoutcause
lost
idk
explosion stars nebula gas Earth
idk
theory, TVshow, story, controversy, big
big, TVshow, flash, creation, explosion
earlydevelopment universe
idk
cosmologicalprinciple, galaxies, biggun, matter, died
big, bang, large, big, catastrophic
beginning, infinite, heat, density, expansion
big bang explosion gas
explosion, pop, beginning, formation, stars
what?
bigbang, instantaneous, nocreator, elementsalreadyexisted, iranoutofwords
idk
galaxies, planets, explosion, rocks, TVshow
fake, big, awesome, startoftime, blackholes
explosion, beginning, life, Sheldon, Leonard
evolution, theory, billionsofyears, period, dot,
start beginning nothing theory universe
lie fake nottrue didnthappen God creation
kaboom beginning universeformation explosion prettylights ah!
boom, explosion, heat, chaos, turmoil
explosion leftovers swirlingmakeseverything
big, bang, God, creation, life
God creation
beginning, energetic, explosion, unstable, expansion
beginning explosion formation particles elements
Sheldon Raj Penny Howard, Leonard
TVshow theory universe light initiation
big, expansion universe, highdensity, hot, longago
peopleareremains, infrared, radiation, photons, lithium

Backwards faded scaffolding laboratory/presentation: assessment case studies

Ever wondered how a Rubrik's Cube™ works? Especially when no longer in its perfect, solved state? So there's nothing much to lose at that point by taking it apart and seeing what's inside. And if done carefully, you could put it back together in its solved state, and no one would be the wiser...except, of course, you.

(This is the seventh Astronomy 210L laboratory at Cuesta College, San Luis Obispo, CA. This course is a one-semester, optional adjunct laboratory to the Astronomy 210 introductory astronomy lecture, taken primarily by students to satisfy their general education science transfer requirement.)

So in this class, hopefully you are becoming experts at doing science and thinking all scienc-y and stuff. You know, like scientists.

And like many scientists do, up to now you've been constructing knowledge by asking and answering research questions.

Many times, instead of building things up, good science is done when tearing things apart--if something doesn't seem quite right, you can fix it; but even if everything was okay in the first place, it is often very instructive to see how something works that was done right.

So today you'll be looking at research questions asked and answered by students from other laboratory classes. Some of these research projects were done right, and some were done...not quite so right, and it will be up to you to determine what's missing/incomplete/wrong, and how to fix it. And this is all part of peer review in science, where quality research should undergo and withstand scrutiny from others, and in the end wind up validated, improved, or sent back to the drawing board if necessary.
(If time allows, the following slides can be shown to students--many of them should able to guess the original devices in these teardown photos.)

Reference:

• Tim Slater, Stephanie Slater, Daniel J. Lyons, Engaging in Astronomical Inquiry, W.H. Freeman & Company, New York, 2010, pp. 43-62,
  http://www.whfreeman.com/newcatalog.aspx?disc=Astronomy+%26+Physics&course=Introduction+to+Astronomy&isbn=1429258608.

Astronomy quiz archive: stellar evolution

Astronomy 210 Quiz 5, Spring Semester 2011
Cuesta College, San Luis Obispo, CA

Section 30676, version 1
Exam code: quiz05s0F7


Section 30676

Quiz 5 results (max score = 40):
   0- 8.0 : **  [low = 2.0]
 8.5-16.0 : ********
16.5-24.0 : ***************  [mean = 21.1 +/- 7.7]
24.5-32.0 : *************
32.5-40.0 : ***  [high = 36.0]

Astronomy quiz archive: stellar evolution

Astronomy 210 Quiz 5, Spring Semester 2011
Cuesta College, San Luis Obispo, CA

Section 30674, version 1
Exam code: quiz05n4rA


Section 30674

Quiz 5 results (max score = 40):
   0- 8.0 : 
 8.5-16.0 : *******  [low = 7.5]
16.5-24.0 : **********  [mean = 22.8 +/- 7.6]
24.5-32.0 : *****************
32.5-40.0 : ***  [high = 40.0]