Astronomy current events question: Europa subsurface ocean oxygen?

Astronomy 210L, Fall Semester 2009
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, "Europa Ocean May Contain Enough
Oxygen to Support Life," October 9, 2009
http://www.astronomy.com/asy/default.aspx?c=a&id=8706

According to a University of Arizona researcher, what is the proposed source for oxygen that may be found in the subsurface oceans of Jupiter's moon, Europa?
(A) Charged particles impacting its icy surface.
(B) Water- and oxygen-rich asteroids.
(C) Open vents in the ice.
(D) Exotic chemical processes on the warm ocean floor.
(E) Photosynthesis.

Correct answer: (A)

Student responses
Sections 70178, 70186, 70200
(A) : 16 students
(B) : 7 students
(C) : 13 students
(D) : 18 students
(E) : 2 students

Astronomy current events question: solar system edge discovery

Astronomy 210L, Fall Semester 2009
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!)

Clara Moskowitz, "Mystery Emissions Found at Solar System Edge," October 15, 2009
http://www.msnbc.msn.com/id/33332042/ns/technology_and_science-space/

What did the NASA Interstellar Boundary Explorer probe recently find at the edge of the solar system?
(A) Rapidly deteriorating heliosphere.
(B) Large planetoid that will pass close by in late 2012.
(C) Ion trails left by the Pioneer 10/11 and Voyager 1/2 probes.
(D) Ribbon of energetic neutral particles.
(E) Diffuse shell of dark matter.

Correct answer: (D)

Student responses
Sections 70178, 70186, 70200
(A) : 3 students
(B) : 3 students
(C) : 6 students
(D) : 43 students
(E) : 0 students

Astronomy current events question: James Webb Space Telescope

Astronomy 210L, Fall Semester 2009
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, "Test Model of James Webb Space Telescope Instrument Ready," October 14, 2009
http://www.astronomy.com/asy/default.aspx?c=a&id=8714

What mission is the joint NASA/European Space Agency James Webb Space Telescope planned to replace?
(A) Cancelled Mars sample return mission.
(B) Repaired Hubble Space Telescope.
(C) Failed Indian Space Agency Chandrayaan moon probe.
(D) Recently crashed LCROSS probe.
(E) Spitzer Space Telescope, out of coolant.

Correct answer: (B)

Student responses
Sections 70178, 70186, 70200
(A) : 0 students
(B) : 28 students
(C) : 5 students
(D) : 8 students
(E) : 14 students

Physics quiz question: down ramp with initial speed

Physics 205A Quiz 4, Fall Semester 2009
Cuesta College, San Luis Obispo, CA

Cf. Giambattista/Richardson/Richardson, Physics, 2/e, Problem 6.28

A 1.2 kg block has an initial speed of 0.75 m/s as it slides down a ramp at a point 0.40 m above a horizontal floor. Neglect friction and drag. What is the final speed of the block along the horizontal floor?
(A) 2.0 m/s.
(B) 2.7 m/s.
(C) 2.8 m/s.
(D) 2.9 m/s.

Correct answer: (D)

Total mechanical energy is conserved, so:

0 = delta(K_tr) + delta(U_grav),
0 = (1/2)*m*(v_f^2 - v_i^2) + m*g*(y_f - y_i),

where y_f = 0, and the common mass m term cancels, such that:

v_f = sqrt(2*g*y_i + v_i^2) = 2.9 m/s.

with v_i = 0.75 m/s, g = 9.80 m/s^2, and y_i = +0.40 m.

Response (C) has v_i = 0; response (B) has a sign error within the square root; and response (A) has both v_i = 0 and a factor error, with v_f = sqrt(g*y_i).

Student responses
Section 72177
(A) : 1 student
(B) : 5 students
(C) : 2 students
(D) : 4 students

Success level: 38%
Discrimination index (Aubrecht & Aubrecht, 1983): 1.00

Online reading assignment question: blue nebula composition

Astronomy 210, Fall Semester 2009
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 question was asked before a presentation on interstellar matter, detailing characteristics of emission, reflection, and dark nebulae.)

A blue nebula is composed of __________. (Graded for completion.)
(A) Hydrogen gas.
(B) Very small dust particles.
(C) Dense clumps of large dust particles.
(D) Helium gas.
(E) (I'm lost, and don't know how to answer this.)

Student responses (pre-instruction)
Sections 70160
(A) : 13 students
(B) : 9 students
(C) : 7 students
(D) : 3 students
(E) : 0 students

Correct answer: (B)

Very small dust particles will scatter short-wavelength (blue) light in all directions more than scattering longer wavelengths, such that this nebula will appear blue in color.

(The same question above was asked of students in a different section, following the presentation on interstellar matter, detailing characteristics of emission, reflection, and dark nebulae.)

Student responses (post-instruction)
Sections 70158
(A) : 9 students
(B) : 14 students
(C) : 8 students
(D) : 4 students
(E) : 3 students

Online reading assignment question: main-sequence lifetimes

Astronomy 210, Fall Semester 2009
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 question was asked before an in-class activity on the evolution of and main-sequence lifetimes of different mass stars.)

_________ stars have the shortest main-sequence lifetime. (Graded for completion.)
(A) Massive.
(B) Medium-mass.
(C) Low-mass.
(D) (There is a tie.)
(E) (I'm lost, and don't know how to answer this.)

Student responses (pre-instruction)
Sections 70160
(A) : 21 students
(B) : 0 students
(C) : 11 students
(D) : 0 students
(E) : 0 students

Correct answer: (A)

A massive star has the shortest main-sequence lifetime (typically less than few millions of years, compared to tens of billions of years for the low-mass main sequence stars).

(The same question above was asked of students in a different section, following an in-class activity on the evolution of and main-sequence lifetimes of different mass stars.)

Student responses (post-instruction)
Sections 70158
(A) : 29 students
(B) : 1 student
(C) : 4 students
(D) : 0 students
(E) : 5 students

Physics quiz question: submarine torpedo-eject recoil

Physics 205A Quiz 4, fall semester 2009
Cuesta College, San Luis Obispo, CA

Cf. Giambattista/Richardson/Richardson, Physics, 2/e, Problem 7.20

"RC VII class submarine firing torpedoes"
rva1945
youtu.be/1aDDlCHjewc

A submarine of mass 7.69×10⁵ kg[*] and initially at rest ejects a torpedo of mass 1.5×10³ kg[**]. The torpedo has a speed of 10 m/s as it leaves the submarine[***]. Neglect external friction/drag during this brief process. The recoil speed of the submarine is:
(A) 2.0×10^–4 m/s.
(B) 2.0×10^–3 m/s.
(C) 6.7×10^–3 m/s.
(D) 2.0×10^–2 m/s.

[*] wki.pe/German_Type_VII_submarine.
[**] wki.pe/G7a_torpedo.
[***] uboatarchive.net/KTBNotesArmament.htm.

Correct answer (highlight to unhide): (D)

Since there are no significant external impulses on the submarine-torpedo system during this brief process, total momentum is conserved, so:

0 = m₁·(v_f1 – v₀₁) + m₂·(v_f2 – v₀₂),

where for the submarine, m₁ = 7.69×10⁵ kg, v₀₁ = 0, v_f1 = ?; and for the torpedo, m₂ = 1.5×10³ kg, v₀₂ = 0, v_f2 = +10 m/s (in the forward direction). So solving for the final velocity v_f1 of the submarine:

0 = m₁·v_f1 + m₂·v_f2,

–m₁·v_f1 = m₂·v_f2,

v_f1 = –m₂·v_f2/m₁ = –(1.5×10³ kg)·(+10 m/s)/(7.69×10⁵ kg) = –1.950585176×10^–2 m/s,

or to two significant figures, the recoil speed of the submarine is the magnitude of its final velocity: 2.0×10^–2 m/s. (Note even with neglecting drag/friction forces, the recoil speed of the submarine is miniscule compared to the torpedo's launch speed, due to the relatively larger mass of the submarine.)

(Response (A) is m₂/(m₁·v_f2); response (B) is m₂/m₁; response (C) is v_f2/m₂.)

Student responses
Sections 70854, 70855
(A) : 3 students
(B) : 9 students
(C) : 2 students
(D) : 34 students

Success level: 70%
Discrimination index (Aubrecht & Aubrecht, 1983): 0.73

Student responses
Section 72177
(A) : 0 students
(B) : 1 student
(C) : 0 students
(D) : 12 students

Success level: 92%
Discrimination index (Aubrecht & Aubrecht, 1983): 0.20

Physics quiz question: work on constant speed sled

Physics 205A Quiz 4, Fall Semester 2009
Cuesta College, San Luis Obispo, CA

Cf. Giambattista/Richardson/Richardson, Physics, 2/e, Problem 6.2

[Version 1]
A Physics 205A student drags a sled across the horizontal floor at a constant speed by a rope that is inclined at angle of 20° above the horizontal. What is the sign of the work done by the normal force on the sled?
(A) Negative.
(B) Positive.
(C) (Zero.)
(D) (Not enough information is given.)

Correct answer: (C)

The normal force on the sled is perpendicular to the horizontal displacement, and thus the work it does on the sled is zero.

Student responses
Sections 70854, 70855
(A) : 2 students
(B) : 10 students
(C) : 11 students
(D) : 0 students

[Version 2]
A Physics 205A student drags a sled across the horizontal floor at a constant speed by a rope that is inclined at angle of 20° above the horizontal. What is the sign of the work done by the weight force on the sled?
(A) Negative.
(B) Positive.
(C) (Zero.)
(D) (Not enough information is given.)

Correct answer: (C)

The normal force on the sled is perpendicular to the horizontal displacement, and thus the work it does on the sled is zero.

Student responses
Sections 70854, 70855
(A) : 9 students
(B) : 9 students
(C) : 12 students
(D) : 0 students

Success level: 47%
Discrimination index (Aubrecht & Aubrecht, 1983): 0.53

Online reading assignment question: hottest star?

Astronomy 210, Fall Semester 2009
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 question was asked subsequent to an OBAFGKM Poetry Slam in-class activity.)

Which star is the hottest? (Graded for completion.)
(A) F5 supergiant.
(B) B0 main-sequence star.
(C) M5 main-sequence star (red dwarf).
(D) A0 white dwarf.

Student responses (pre-instruction)
Sections 70160
(A) : 5 students
(B) : 12 students
(C) : 4 students
(D) : 13 students

Correct answer: (B)

On an H-R diagram, and/or using the OBAFGKM spectral type sequence (running from hottest to coolest), B0 is the hottest start of the choices listed. (Note that the usual "I'm lost, and don't know how to answer this" response for non-exam questions was inadvertently left out of this question.)

(Students were then prompted to fill in a text box online to justify their answer.)

Briefly explain your answer, about your choice for smallest star. (Graded for completion.)

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

"OBAFGKM"

"The hotter it gets, the brighter the light; hence white is the hottest."

"Because it has white next to it, White is one of the hottest stars"

"because on the Kelvin scale its the hottest, and B is the farthest away"

"it has the hottest temp because its white and its in the A0 quadrant."

"The main sequence is about 10,000 degress and the white dwarf is about 7,000"

"because it is blue"

"OBAFGKM, moving from hottest to coolest. B comes earliest in the sequence, as illustrated on the star chart given in class."

"B' stands for blue which is the 2nd hottest colored temp. That means the main sequence star is hotter than the rest, even the white dwarf.
eenie meanie mynee mo"

"because i'm smart and i pay attention"

"Im not quite sure"

"B0 main-sequence is higher than the other choices."

"This star has the hottest temperature and the largest luminosity on the star chart"

"according to the memorization tool you had us make up, B comes before all the other letters."

"From hottest to coolest, B-A-F-M. Main sequence star is hottest, based on it's letter (B) being second in line for hottest star, behind O."

"hey."

"The white dwarf is the hottest star because white is the hottest you can go on the spectrum."

"because its white"

"on the S and G chart b level stars are the hottest."

"i looked on the cheat sheet you gave us and using process of elimination, i chose the answer that was correct. to chose any other answer would not be correct."

"It just is."

"I don't know"

"OBAFGKM or something like that... either way, B comes before A, M, or F"

"B is closet to the left. which is the hottest."

"the one that is blue"

"White dwarf is smaller but very compacted and dense"

"O, B, A, F, G, K, M.... This sequence goes from left to right... Left is the hottest, so B0 must be the hottest since there are no O stars available! Right?"

"because B is higher surface temp than all the others except for O and on the chart the hottest is main sequence then all the other options."

091013-NCCpreOBAFGKM
http://www.flickr.com/photos/waiferx/4023867044/
Originally uploaded by Waifer X

Wordle.net tag cloud for the pre-OBAFGKM Poetry Slam NCC section (http://www.wordle.net/show/wrdl/1240070/Untitled).

(A different section of this class was given the same online reading assignment, but was asked this question after an OBAFGKM Poetry Slam in-class activity.)

Student responses (post-instruction)
Sections 70158
(A) : 2 students
(B) : 18 students
(C) : 1 student
(D) : 8 students

"Because its between 20,000 and 30,000 in temp in the chart. Its at the farthest left."

"because its white."

"The hottest star is M5 because the temperature for stars goes..OBAFGKM."

"Its Bigger"

"because the white dwarf star is hot..."

"White = Hot"

"not really sure...this was just a guess according to figure 7-7 in Ch. 7 readings."

"A class-B star has a temperature range of about 10,000 - 30,000 degrees K, which is hotter than any of the other options."

"i guessed"

"I don't know..."

"The brighter the main sequence star is the hotter it gets. A 'B' star is the farthest left of these four on the spectrum"

"A0 is the hottest a star can get being over 10000 kelvin"

"has a greater surface temperature on the spectrum then a main sequence star."

"I am not sure."

"white is the hotest color"

"White Hot"

"white hot"

"because of the size and luminosity ratio copared to the other stars"

"On the chart we got in class, the BO main-sequence star is the hottest."

"I can hardly remember the chart, but i'm sure its the supergiants cuz they are the highest up there on the chart :P"

"according to the graph its the hottest because the sun is about 6000 kelvin and a BO mainsequence has a surface temperature of 20,000 to 50,000 kelvin"

"Color reflects temperature and white is the hottest"

"using the Hertzsprung-Russell diagram we see that A stars are hotter than B,F, and M stars. the number after the letter is simply more specific classification which is in this comparison unnecessary."

"because B stars are hotter than the others"

"The red dwarf stretches across to a temperature of 50,000 being the hottest temperature while the others fall short of that degree."

"On the star diagram the BO main sequence stars are furthest on the temperature scale."

"B0 main-sequence star is the hottest because it is blue, closest to the left."

"In the spectral sequence, B stars are hotter than all but O stars which are the hottest."

"a supergiant star is the hottest because it is the most lumionous and it has a large section in the highest tempature on the H-R diagram."

"White is hotter than red."

"Because in the sequence OBAFGKM (with O being the hottest and M the coolest), B is the closest to O in the snaswers provided."

"Thats what these notes say..."

"because white is the hottest color on the spectrum"

"The first two letters that classify the temp. of stars are O and B since there is no O star listed it would be the star in the B zone."

091014-SLOpostOBAFGKM
http://www.flickr.com/photos/waiferx/4023867274/
Originally uploaded by Waifer X

Wordle.net tag cloud for the post-OBAFGKM Poetry Slam SLO section (http://www.wordle.net/show/wrdl/1240073/Untitled).

Astronomy current events question: LCROSS mission outcome

Astronomy 210L, Fall Semester 2009
Cuesta College, San Luis Obispo, CA

Students are assigned to read online articles on current astronomy events, and take a short current events quiz during the first 10 minutes of lab. (This motivates students to show up promptly to lab, as the time cut-off for the quiz is strictly enforced!)

Alan MacRobert, "The LCROSS Impact, Continued," October 11, 2009
http://www.skyandtelescope.com/news/home/63766222.html

What was the somewhat unexpected result of the NASA LCROSS mission lunar impact?
(A) No collision was observed.
(B) The impact was smaller than expected.
(C) Evidence of liquid water waves.
(D) A new faint, tilted ring surrounding the Moon.
(E) Brief disruption in satellite TV communications.

Correct answer: (B)

Student responses
Sections 70178, 70186, 70200
(A) : 4 students
(B) : 20 students
(C) : 5 students
(D) : 0 students
(E) : 0 students

Astronomy current events question: First Family star party

Astronomy 210L, Fall Semester 2009
Cuesta College, San Luis Obispo, CA

Students are assigned to read online articles on current astronomy events, and take a short current events quiz during the first 10 minutes of lab. (This motivates students to show up promptly to lab, as the time cut-off for the quiz is strictly enforced!)

Kelly Beatty, "Stargazing with the Obamas," October 8, 2009
http://www.skyandtelescope.com/news/63749172.html

What was the special occasion commemorated by the White House Star Party, which was attended by the President and the First Lady?
(A) Washington D.C. Light Pollution Darkout 2009.
(B) 2009 Nobel Peace Prize.
(C) NASA LCROSS mission lunar impact.
(D) Renovation of the White House Observatory.
(E) International Year of Astronomy 2009.

Correct answer: (E)

Student responses
Sections 70178, 70186, 70200
(A) : 17 students
(B) : 4 students
(C) : 8 students
(D) : 4 students
(E) : 22 students

Astronomy current events question: Saturn's new ring system

Astronomy 210L, Fall Semester 2009
Cuesta College, San Luis Obispo, CA

Students are assigned to read online articles on current astronomy events, and take a short current events quiz during the first 10 minutes of lab. (This motivates students to show up promptly to lab, as the time cut-off for the quiz is strictly enforced!)

Kelly Beatty, "Saturn's New King of the Rings," October 7, 2009
http://www.skyandtelescope.com/news/63685982.html

According to University of Virginia researchers, what is the source of Saturn's newly discovered tilted ring system?
(A) Captured asteroids.
(B) Material from one of its moons.
(C) A disintegrated comet.
(D) Magnetic storm eruptions.
(E) Solar winds.

Correct answer: (B)

Student responses
Sections 70178, 70186, 70200
(A) : 6 students
(B) : 39 students
(C) : 4 students
(D) : 4 students
(E) : 3 students

Astronomy current events question: MESSENGER final destination

Astronomy 210L, Fall Semester 2009
Cuesta College, San Luis Obispo, CA

Students are assigned to read online articles on current astronomy events, and take a short current events quiz during the first 10 minutes of lab. (This motivates students to show up promptly to lab, as the time cut-off for the quiz is strictly enforced!)

Kelly Beatty, "Messenger's Third "Taste" of Mercury," September 29, 2009
http://www.skyandtelescope.com/news/62766047.html

The NASA MESSENGER spacecraft recently made a third and final flyby past Mercury. What is its final destination in 2011?
(A) Orbiting around Mercury.
(B) Flying through a solar flare.
(C) Crashing into a shadowed crater on Mercury.
(D) Polar orbit around the Sun.
(E) Asteroid 7861 Messenger.

Correct answer: (A)

Student responses
Sections 70178, 70186, 70200
(A) : 16 students
(B) : 2 students
(C) : 4 students
(D) : 4 students
(E) : 0 students

Astronomy quiz question: same luminosity white dwarf vs. red dwarf

Astronomy 210 Quiz 4, Fall Semester 2009
Cuesta College, San Luis Obispo, CA

A white dwarf will be ___________ compared to a red dwarf that has the same luminosity.
(A) cooler and smaller.
(B) hotter and smaller.
(C) cooler and larger.
(D) hotter and larger

Correct answer: (B)

From Wien's law, white dwarfs must be hotter than red dwarfs. From the Stefan-Boltzmann law (luminosity proportional to size and temperature^4), since the white dwarf has the same luminosity, but is at a higher temperature than the red dwarf, then the white dwarf must be smaller in size.

Section 70160
(A) : 1 student
(B) : 32 students
(C) : 2 students
(D) : 8 students

(Cf. blog posts Astronomy clicker question: same luminosity main sequence vs. giant star, Astronomy quiz question: same temperature main sequence vs. giant star.)

Success level: 76% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.38

Astronomy quiz question: apparent magnitude and distance

Astronomy 210 Quiz 4, Fall Semester 2009
Cuesta College, San Luis Obispo, CA

[Version 1]
Achernar is a star located 36.2 parsecs away from Earth, and has an apparent magnitude of m = +0.51. If Achernar were relocated to 10 parsecs away from Earth, its apparent magnitude would:
(A) get brighter.
(B) remain the same.
(C) get dimmer.
(D) (Not enough information is given.)

Correct answer: (A)

The apparent magnitude would get brighter, as the star would be moving closer to Earth.

Section 70158
(A) : 32 students
(B) : 4 students
(C) : 7 students
(D) : 1 student

Success level: 74% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.46

[Version 2]
Ross 154 is a star located 4.08 parsecs away from Earth, and has an apparent magnitude of m = +13.3. If Ross 154 were relocated to 10 parsecs away from Earth, its apparent magnitude would:
(A) get brighter.
(B) remain the same.
(C) get dimmer.
(D) (Not enough information is given.)

Correct answer: (C)

The apparent magnitude would get dimmer, as the star would be moving closer away from Earth.

Section 70160
(A) : 0 students
(B) : 0 students
(C) : 43 students
(D) : 0 students

Success level: 100% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0

Astronomy quiz question: same temperature main sequence vs. giant star

Astronomy 210 Quiz 4, Fall Semester 2009
Cuesta College, San Luis Obispo, CA

A main sequence star will be ___________ compared to a giant star that has the same temperature.
(A) less luminous and smaller.
(B) less luminous and larger.
(C) more luminous and smaller.
(D) more luminous and larger.

Correct answer: (A)

From an H-R diagram, main sequence stars that are the same temperature as giants will be less luminous than the giants. From the Stefan-Boltzmann law (luminosity proportional to size and temperature^4), since the main sequence star has less luminosity, but is the same temperature as the giant, then the main sequence star must be smaller in size.

Section 70158
(A) : 35 students
(B) : 1 student
(C) : 7 students
(D) : 1 student

(Cf. blog post Astronomy clicker question: same luminosity main sequence vs. giant star.)

Success level: 81% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.37

Astronomy in-class activity: OBAFGKM poetry slam (NCC)

Astronomy 210, Fall Semester 2009
Cuesta College, San Luis Obispo, CA
(North County Campus)

Astronomy 210 In-class activity 14: OBAFGKM Poetry Slam

Students were instructed to use at least OBAFGKM, and/or part or all of the additional OBAFGKMRNSC or OBAFGKMLT extensions to individually write an original, coherent and an appropriate (nothing worse than "PG-13" rated!) mnemonic, and to give a rousing reading of their OBAFGKM mnemonic poem for the class.

Oh Boy!! Asteroid Fragments are Gonna Kill Me...
--C. A.

One Big Ape Fights Giant Killer Moths
--B. A.

On Board A Fire Grew Keeping Me Trapped
--A. B.

Offshore Boaters Are Finding Giant Kelp Mounds
--R. B.

Only Baseless Accusations From Gluttonous Kings Make Royal Necks Sliced Clean
--D. B.

On Birthdays A Funny Grandma Karate-Chops a Mongoose
--L. B.

Oh Boy A Flying Giraffe King Married Len Tonight
--K. C.

Ooooooo Balls A Fiery Gnome Kicked Me Running Naked South of Chile
--T. D.

Oh Boy, Another Film Goes. Keeping Mediocre Ratings. Never Settle. Comedies!
--K. G.

Oh Brother A Flying Gorilla Killed Me
--R. H.

Over Board A Female Goat Kicked Me
--R. J.

On Board A Fairly Giant Killer Missile
--R. K.

Oh Be Afraid, Fat Grandmas Kill Monkeys
--C. L.

October Brings A Frightening Group! Kids Masked Like Turtle Ninjas
--J. L.
Oh Boy, Another Frustrated Girl Kicks Man
--D. M.

Oh Boy An F Grade Kills Me
--S. M.

Oh Bummer A Freaking Gorilla Killed My Lion, Theodore
--T. O.

Oh Banks Are Finally Giving Kind Money
--A. O.

Oh But Another Fine Guitarist Kiboshes My Loathsome Tabulating
--S. R.

Obviously, Bacon And Fat Grease Kills Men
--A. R.

Our Brother And Father Got Kinda Mad
--J. R.

Outrageous Builders Are Farming Giant Killer Monsters
--J. R.

Only Baby Animals Freak-out Good Kids' Mothers
--C. S.

Only Boys Attend Fighting Gangster Karate Movies
--A. S.

Only Bourne, A Fighter, Gets Killing Men
--K. S.

Oh Boy A Fat Girl Kissed Me
--A. T.

Oh Bob Accidentally Farts Gases Keeps Me Making Rare Noises
--Anonymous

Out Back A Fat Goat Kills Men
--Anonymous

Previous post: Astronomy in-class activity: OBAFGKM poetry slam instructions.

Astronomy in-class activity: OBAFGKM poetry slam (SLO)

Astronomy 210, Fall Semester 2009
Cuesta College, San Luis Obispo, CA
(San Luis Obispo Campus)

Astronomy 210 In-class activity 14: OBAFGKM Poetry Slam

Students were instructed to use at least OBAFGKM, and/or part or all of the additional OBAFGKMRNSC or OBAFGKMLT extensions to individually write an original, coherent and an appropriate (nothing worse than "PG-13" rated!) mnemonic, and to give a rousing reading of their OBAFGKM mnemonic poem for the class.

Oh, Booze And Food Gets Kids Merry
--S. A.

Oh Boy, A Flying Gorilla Killed Ma!
--S. A.

Oh Buddy, Astronomy Frequently Gives Killer Migraines
--M. A.

Ouch! Bees Are Finally Gonna Kill Me.
--K. B.

Obama Bankrupts America; Fact. Gets KGB Membership.
--L. B.
Overweight Bats Are Fighting Gorillas in the Kona Mountains
--H. C.

Oo Bama Asked for Gorilla King Meat
--R. C.

Ogres Bite Americans For Giants Kill Monks
--H. C.

Obese Black women Are Frickin' Great Kitchen Moms
--B. D.

Obese Blue Aliens Fight Gassy Killer Medications
--J. E.

Oh Boy, Anyone Feeling Grumpy? Kinda? Maybe?
--M. F.

Only Betray A Friend if you're Going Krazy Man!! it's Really Not So Cool.
--L. G.

Only Bad Ass Fighters Get Killer Marks Like Tigers
--L. G.
Otter Babies Are Fluffy Giant Killer Machines
--A. G.
Oh Brother! A Fake Green Killer Mantaray!
--M. H.

Outnumbered British Admirals Fight Gallantly Killing Many Rebellious New Seamen
--M. H.

Open Before Another Fairy Gnome Kicks Me
--E. J.

Only Bewildered Astronauts Fear Ghenghis Khan's Machete
--B. J.
Octoberfest Beers Are Freakin Good @ Keeping Me Lightly Trashed
--J. J.

Octopus-Bears Are Freakin' Great Killing Machines
--K. J.
Our Bees Are Ferocious Ghosts! Killing Me...Like Tycho!
--C. K.

Only Bad-A**es For Governor, 'Kay Man?
--N. K.

On Blankets Are Flying Geese Kicking Mud
--B. L.

Oh Boy A Fat Guy Kicked Me
--J. M.

Obnoxious Bretheren Amplified Following Gallons of Killer Margaritas
--A. M.
One Big Astronomy Final. God Kill Me.
--P. M.

Obviously Bars Are For Gathering Kinky Moms
--T. M.

Octopuses Back Away From Gigantic Kayaks Mysteriously
--B. P.Offering Beer At Family Gatherings Killed Mom
--L. P.
"Only Bears Are Fully Godless Killing Machines," Reports Newsman Stephen Colbert, Later Tonight.
--I. P.
Only Big Asteroids Force Giant Killer Monsoon
--J. R.

On Birthdays, A Fat Gut Kicks Me
--J. R.

Oh Be A Freakin' Guy, Kill Mice Lighting TNT!
--J. R.

Only Big Ass Funky Gorillas Kick Monkeys
--T. S.

Orangutans Bully All Furry Gorillas Kissing Monkeys
--R. S.

Oaring Back and Forth, Gallic King McFinnigan Returned North
--M. S.

Orange Belugas Assume Fred Gives Killer Makeovers
--D. S.

Outrageous Bitches Always Feel Good Killing Men
--T. S.

One Ballistic Angry Farmer Grew Killer Melons!!!
--M. S.
Oh Baby A Few Gushers Kindly More
--N. T.

Only Bob And Fred Go Kayaking Mondays
--N. T.

Only Bitchin' Acronyms Form Gnarly Knowledgeable Minds
My Krazy Glue Fixes All Broken Objects
--A. W.

Orange Bees Ally Free Giants Killing Mankind
--P. W.

Oak Branches Are Fairly Good at Killing Me
--M. Z.

Previous post: Astronomy in-class activity: OBAFGKM poetry slam instructions.

Astronomy midterm question: telling "moon-time"

Astronomy 210 Midterm 1, fall semester 2009
Cuesta College, San Luis Obispo, CA

Shown at right is an excerpt from a comic strip (Baby Blues, Rick Kirkman and Jerry Scott, King Features Syndicate, August 2, 2009). Given the phase of the moon shown here, discuss a plausible time at night for the events depicted in this comic strip, using a diagram showing the positions of the sun, moon, and Earth.

Solution and grading rubric:

• p:
  Correct. Identifies the phase as waxing gibbous, which is highest overhead at 9 PM (rising at 3 PM, and setting at 3 AM), using a diagram of the sun, moon, and Earth. May choose 9 PM, or anytime between sunset (6 PM) to 3 AM as being a plausible time for the events depicted in the comic strip.
  
• r:
  Nearly correct (explanation weak, unclear or only nearly complete); includes extraneous/tangential information; or has minor errors. May include 3 PM in a range of plausible times, or diagram has minor inconsistencies/errors.
  
• t:
  Contains right ideas, but discussion is unclear/incomplete or contains major errors. Problems with either diagram, phase, or time.
  
• v:
  Limited relevant discussion of supporting evidence of at least some merit, but in an inconsistent or unclear manner. Problems with diagram, phase, and time.
  
• x:
  Implementation/application of ideas, but credit given for effort rather than merit.
  
• y:
  Irrelevant discussion/effectively blank.
  
• z:
  Blank.
  

Grading distribution:
Section 70160
p: 18 students
r: 2 students
t: 6 students
v: 12 students
x: 1 student
y: 2 students
z: 1 student

A sample "p" response (from student 1022), with a plausible range of times at night:
Another sample "p" response (from student ), with one chosen plausible time at night:
A sample "r" response (from student ), with daylight hours (3 PM-6 PM) included in the range of plausible times at night:
A sample "t" response (from student 5413), with the correct phase and a plausible time at night, but with a problematic diagram:

Education research: preliminary feedback on clickers (Chemistry 210FL, Cuesta College, Fall Semester 2009)

Cuesta College students taking Chemistry 210FL (introductory chemistry) at Cuesta College, San Luis Obispo, CA use clickers (Classroom Performance System, einstruction.com) during lecture.

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

These are the complete survey results. Analysis will be forthcoming after more data has been compiled from future semesters. Values for the mean and standard deviations are given next to the modal response category for each question. Note that the order of questions within sections II and III were randomly scrambled for each student.

Learning Resource Survey
Cuesta College
Chemistry 210FL Fall Semester 2009 sections 72122, 72234, 70302, 70306, 71813, 72093
(N = 32)

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


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

II.1 Lecture by instructor.
1. Strongly disagree      0 : 
2. Disagree               1 : *
3. Neutral                3 : ***
4. Agree                  8 : ********
5. Strongly agree        20 : ********************  [4.5 +/- 0.8]
     
II.2 Working in groups on FAL (Facilitated Assisted Learning) activities.  
1. Strongly disagree      1 : *
2. Disagree               6 : ******
3. Neutral                3 : ***
4. Agree                  8 : ********
5. Strongly agree        14 : *******************  [3.9 +/- 1.2]

II.3 Using clickers to participate in class.
1. Strongly disagree      0 : 
2. Disagree               4 : ****
3. Neutral               11 : ***********  [3.7 +/- 1.0]
4. Agree                  9 : *********
5. Strongly agree         8 : ********

II.4 Reading the textbook.
1. Strongly disagree      0 : 
2. Disagree               1 : *
3. Neutral                5 : *****
4. Agree                 13 : *************  [4.2 +/- 0.8]
5. Strongly agree        13 : *************

II.5 Demonstrations/videos in class.      
1. Strongly disagree      0 : 
2. Disagree               1 : *
3. Neutral               10 : **********  [3.9 +/- 0.9]
4. Agree                 10 : **********
5. Strongly agree        10 : **********

II.6 Interacting with other students during class.   
1. Strongly disagree      0 : 
2. Disagree               1 : *
3. Neutral                4 : **** 
4. Agree                 15 : ***************  [4.2 +/- 0.8]
5. Strongly agree        12 : ************

II.7 Interacting with other students outside of class.
1. Strongly disagree      1 : *
2. Disagree               3 : ***
3. Neutral                9 : *********
4. Agree                 10 : **********  [3.7 +/- 1.1]
5. Strongly agree         9 : *********

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

III.1 I like using clickers. 
1. Strongly disagree      0 : 
2. Disagree               2 : **
3. Neutral               15 : ***************  [3.5 +/- 0.8]
4. Agree                 11 : ***********
5. Strongly agree         4 : ****

III.2 Clickers helped me understand lectures better.   
1. Strongly disagree      1 : *
2. Disagree               9 : *********
3. Neutral                9 : *********
4. Agree                 11 : ***********  [3.1 +/- 1.0]
5. Strongly agree         2 : **

III.3 I would recommend using clickers in future semesters of this class. 
1. Strongly disagree      0 : 
2. Disagree               2 : **
3. Neutral               14 : **************  [3.5 +/- 0.7]
4. Agree                 13 : *************
5. Strongly agree         3 : ***

III.4 I will avoid other classes using clickers in future semesters. 
1. Strongly disagree      7 : ************
2. Disagree              13 : ******************  [2.2 +/- 1.5]
3. Neutral               11 : ***********
4. Agree                  0 : 
5. Strongly agree         1 : *

III.5 Clickers were a positive experience.    
1. Strongly disagree      0 : 
2. Disagree               1 : *
3. Neutral               13 : *************
4. Agree                 15 : ***************  [3.6 +/- 0.7]
5. Strongly agree         3 : ***

III.6 Too much time in class was spent using clickers.   
1. Strongly disagree      5 : *****
2. Disagree              15 : ***************  [2.4 +/- 1.1]
3. Neutral                8 : ********
4. Agree                  3 : ***
5. Strongly agree         1 : *

III.7 Too many clicker questions were asked. 
1. Strongly disagree      5 : *****
2. Disagree              17 : ************  [2.3 +/- 1.2]
3. Neutral                7 : *******
4. Agree                  2 : **
5. Strongly agree         1 : *
     
III.8 Using clickers was difficult. 
1. Strongly disagree     13 : *************
2. Disagree              15 : ***************  [1.8 +/- 2.4]
3. Neutral                2 : **
4. Agree                  0 : 
5. Strongly agree         2 : **

IV. (Optional.) Please type in any comments you may have regarding 
    the use of clickers in Chemistry 210FL.

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

"The clickers were quite nice once they were working. I wish there wer a little bit more clicker questions on lecture examples."

"They are easy to use."

"I think that the clickers are a great idea and can be useful in class discussions. Although in the way that we are using them, simply to turn in answers without understanding the results or review the questions, they are not as beneficial as they could be."

"If we used the clickers as a statistical viewpoint only and spent more time reviewing the questions that were asked of us, then the clickers would become more helpful in an education way, opposed to the point/credit purpose they serve now."

"I believe that clickers are just another way to get money out of us. They can be useful, but you must buy the clicker and register it. It is too much money. We could have different kinds of quizzes and other kinds of participation in class."

"I could take them or leave them."

"I think having jump start questions were a good idea, since it made you read the next chapter and I also felt that it helped during lecture to have a 'heads up' on what we were going to cover next."

"I think now that we seem to have the clickers all working, that the program is very useful and is a creative way of learning."

"I think FALs should be an optional study groups. It is bad enough that we don't get the complete credit time for time spent in class(s). But on top of it, an extra hour is required to force us to work together. The idea of an FAL is great. but it would be much better to have Chemlab like Mathlab, leave it optional. People will work together anyway with friends they make in class during clicker quiz's or in lab. Demo videos are cool but with a lab they are not really needed. its cooler to see it for real in a lab then to see it in a video. I see a lot of interest is directed in the use of clickers. Clickers are fine. The way in which you chose to use them is good and time effective, you don't over use them. and the amount of class time consumed is about 10 minutes per week. so 7% of the in class lecture time is used to help you determine what is least understood. granted people will work together to get answers so the 100% correct may not mean 100% understood. but a low % would grantee confusion. I know there is debate over the effectiveness of clickers. I support them, they are not expensive and they help the teacher keep in touch with their classes progress between tests. 'Clickers helped me understand lectures better.' I agree with this because it adds to exposure and interactivity in the subject. I is like when your having a hour long conversation with someone and after while you kinda zone out. ahuh ahuh ahuh, you know. so this makes you think and apply what your doing. it breaks up the lecture a bit and makes the class more interesting. That said. I believe reading the textbook, being lectured and asking questions is adequate to learn the subject. Your a great teacher, and [the lab instructor] is a great lab instructor. both of you add alot of color and enjoyment to the subject. I feel fortunate to have a positive first exposure to learning the subject. I read a book in the past called Feynman's Rainbow. It was a terrible book by a terrible failed chemist, failed physicist and it turned me off to chemistry. But it turns out that chemistry is no so bad after all."

"I do like the option of working with other students for clicker quizes in clas"

"I have no questions, currently."

"This class is well balanced in time spent on lecture, demonstrations, using the clicker, and answering questions from students. I had a previous class that used the clicker and I felt that it hindered my ability. However, [the instructor] does an excellent job using the clickers in constructive ways that help the students and also allow her know if the students are understanding the concepts. The clickers are definitely an asset to this class."

"I am often at a neutral position with clickers because you can just as easily quiz students without them. This change in form would help the students with money because of the cost of not only the clicker but to sign up in the class as well. However it is much easier to link the clickers rather than print out 40 copies of a test, that is why I find myself at a neutral position."

"I find the clicker to be a nice tool and great time saver for instructors when grading and record student data, but it's just another material cost to have to afford when I am seem to be struggling already to pay for the textbook, FAL packet as well as chemistry lab booklet."

"I think the clicker quizzes are fun and challenging way to get the students to pre-read the course material."

"I do not mind the clickers what so ever, my only thing is i found it very expensive. This is the only class i have ever taken that has required the clicker an it was i thought i process. Buying it was thirty dollars, then another fifteen to register the thing. I find using the small ten point scantrons is easier. I can understand that the clicker is faster an better for the instructor, but also expensive for the students."

"The only comment I have is that the clickers would be more desirable if they were in the classroom ready to check out each time we use them. Carrying them around and buying them is the only inconvenience. Otherwise I like using them."

Astronomy midterm question: midnight Venus?

Astronomy 210 Midterm 1, fall semester 2009
Cuesta College, San Luis Obispo, CA

Consider the following excerpt regarding viewing Venus near midnight:

"When [Harry, Ron, Hermione] reached the top of the Astronomy Tower at eleven o'clock they found a perfect night for stargazing, cloudless and still... They entered the precise positions of the stars and planets they were observing... Half an hour passed, then an hour... Harry put his eye...to his telescope and refocused it, now examining Venus."
--J. K. Rowling, Harry Potter and the Order of the Phoenix, Scholastic (2003), pp. 718-719.

Discuss whether this is plausible or implausible. Support your answer using a diagram showing the positions of the sun, Venus, and Earth.

Solution and grading rubric:

• p:
  Correct. Discusses the implausibility of this scenario by drawing a diagram with Venus' orbit closer in to the sun than Earth's orbit, making it not possible for midnight observer (assumed to be at/near the equator) to observe Venus anywhere in its inner orbit.
  
• r:
  Nearly correct (explanation weak, unclear or only nearly complete); includes extraneous/tangential information; or has minor errors. Draws Venus in a geocentric orbit (and along or near the sun-Earth line) and argues implausibility based on this model (which is incorrect, but does reproduce the relative maximum possible angular separation between the sun and Venus).
  
• t:
  Contains right ideas, but discussion is unclear/incomplete or contains major errors. Argues plausibility based on a problematic heliocentric diagram, with Venus' orbit larger than Earth's orbit. Or argues implausibility based on a correct heliocentric diagram, with Venus' orbit closer in to the sun than Earth's orbit).
  
• v:
  Limited relevant discussion of supporting evidence of at least some merit, but in an inconsistent or unclear manner. May discuss evening/morning star nature of Venus, elliptical orbital shapes, prograde/retrograde motion, phases, etc.
  
• x:
  Implementation/application of ideas, but credit given for effort rather than merit.
  
• y:
  Irrelevant discussion/effectively blank.
  
• z:
  Blank.
  

Grading distribution:
Section 70160
p: 18 students
r: 2 students
t: 6 students
v: 12 students
x: 1 student
y: 2 students
z: 1 student

A sample "p" response (from student 2416):
A sample "t" response (from student 5474), with Venus' heliocentric orbit larger than Earth's:
A sample "y" response (from student 2662), given credit for effort rather than merit:

Astronomy midterm question: radio telescope locations

Astronomy 210 Midterm 1, Fall Semester 2009
Cuesta College, San Luis Obispo, CA

[20 points.] Decide whether a proposed radio telescope should be placed on the ground or in outer space in order to be most cost-effective and be able to most efficiently gather astronomical data. Explain the reasoning behind your decision, in terms of relevant criteria discussed in this class.

Solution and grading rubric:

• p = 20/20:
  Correct. In general, the atmosphere is relatively transparent to radio waves, such that a ground-based telescope would be cheaper and just as effective as a space-based radio telescope. May argue for high-altitude or space-based radio telescopes for specific wavelengths that the atmosphere is relatively opaque for (e.g., FM/AM).
  
• 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. Does not specifically discuss the relative transparency of Earth's atmosphere to radio waves, but only in general terms such as disruption, inteference, distortion.
  
• v = 8/20:
  Limited relevant discussion of supporting evidence of at least some merit, but in an inconsistent or unclear manner.
  
• 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 70160
p: 37 students
r: 0 students
t: 5 students
v: 0 students
x: 0 students
y: 0 students
z: 0 students

A sample "p" response (from student 7144), using toys made of solid gold as an analogy:
Another "p" response sample (from student 6363), narrowing the discussion of radio waves to the FM/AM band:
Yet another "p" response (from student 1022) discussing the criteria posed by the different types of radio waves:

Astronomy midterm question: telling "Moon-time"

Astronomy 210 Midterm 1, Fall Semester 2009
Cuesta College, San Luis Obispo, CA

[20 points.] Shown at right is an excerpt from a comic strip (Wizard of Id, Brant Parker and Johnny Hart, Creators Syndicate, June 28, 2009). Given the phase of the moon shown here, discuss a plausible time at night for the events depicted in this comic strip, using a diagram showing the positions of the sun, moon, and Earth.

Solution and grading rubric:

• p = 20/20:
  Correct. Identifies the phase as waning crescent, which is highest overhead at 9 AM (rising at 3 AM, and setting at 3 PM), using a diagram of the sun, moon, and Earth. May choose anytime between 3 AM to 6 AM (sunrise) as being a plausible time at night for the events depicted in the comic strip.
  
• r = 16/20:
  Nearly correct (explanation weak, unclear or only nearly complete); includes extraneous/tangential information; or has minor errors. May include 9 AM or any time after sunrise, or diagram has minor inconsistencies/errors.
  
• t = 12/20:
  Contains right ideas, but discussion is unclear/incomplete or contains major errors. Problems with either diagram, phase, or time.
  
• v = 8/20:
  Limited relevant discussion of supporting evidence of at least some merit, but in an inconsistent or unclear manner. Problems with diagram, phase, and time.
  
• 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
p: 15 students
r: 13 students
t: 7 students
v: 19 students
x: 0 students
y: 0 students
z: 0 students

A sample "p" response (from student 4614):

A sample "r" response (from 1623), who at least finds it strange that it is apparently dark outside:

Astronomy midterm question: ideal/non-ideal viewing conditions

Astronomy 210 Midterm 1, Fall Semester 2009
Cuesta College, San Luis Obispo, CA

[20 points.] Consider the following excerpt regarding viewing stars and planets at night:

"When [Harry, Ron, Hermione] reached the top of the Astronomy Tower at eleven o'clock they found a perfect night for stargazing, cloudless and still. The grounds were bathed in silvery moonlight... Each of them set up his or her telescope and...entered the precise positions of the stars and planets they were observing..."
--J. K. Rowling, Harry Potter and the Order of the Phoenix, Scholastic, New York, NY, 2003, pp. 718-719.

Discuss both the ideal and non-ideal conditions that would have affected telescopic observations on that night. Support your answer using factors that relate to the three telescope powers.

Solution and grading rubric:

• p = 20/20:
  Correct. Ideal: lack of atmospheric turbulence means that resolving power is not adversely affected. Non-ideal: moonlight will adversely affect the light-gathering power to image fainter stars.
  
• r = 16/20:
  Nearly correct (explanation weak, unclear or only nearly complete); includes extraneous/tangential information; or has minor errors. Discusses both ideal and non-ideal factors, but one citation from excerpt is problematic; or most generally discusses all factors that may affect viewing, but does not specifically apply it to the excerpt.
  
• t = 12/20:
  Contains right ideas, but discussion is unclear/incomplete or contains major errors. Correctly discusses only one of the ideal/non-ideal conditions specified in the excerpt.
  
• v = 8/20:
  Limited relevant discussion of supporting evidence of at least some merit, but in an inconsistent or unclear manner.
  
• 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
p: 22 students
r: 10 students
t: 20 students
v: 2 students
x: 0 students
y: 0 students
z: 0 students

A sample "p" response (from student 2522):

A sample "r" response (from student 7392), neglecting to address the light-pollution caused by moonlight, but also citing additional details from the book not specifically included in the above excerpt:

Astronomy midterm question: low west sunset Venus?

Astronomy 210 Midterm 1, fall semester 2009
Cuesta College, San Luis Obispo, CA

Consider the following excerpt regarding viewing Venus just after sunset:

"The stars were just now appearing, but to the west, a single point of light glowed brighter than any other. Langdon smiled when he saw it. It was Venus."
--Dan Brown, The Da Vinci Code: A Novel, Random House, New York, NY, 2003, p. 589.

Discuss whether this is plausible or implausible. Support your answer using a diagram showing the positions of the sun, Venus, and Earth.

Solution and grading rubric:

• p = 20/20:
  Correct. Discusses the plausibility of this scenario by drawing a diagram with Venus' orbit closer in to the sun than Earth's orbit, making it possible for an observer at sunset to observe Venus low on the west horizon.
  
• r = 16/20:
  Nearly correct (explanation weak, unclear or only nearly complete); includes extraneous/tangential information; or has minor errors. Draws Venus in the correct position in its orbit relative to Earth such that it would be seen just after sunset, but concludes that this would be implausible.
  
• t = 12/20:
  Contains right ideas, but discussion is unclear/incomplete or contains major errors. Argues plausibility or implausibility based on drawing Venus in its orbit relative to Earth such that it would be visible in the east horizon at sunrise, or is transiting the sun.
  
• v = 8/20:
  Limited relevant discussion of supporting evidence of at least some merit, but in an inconsistent or unclear manner. Draws a problematic diagram with Venus' orbit larger than Earth's orbit, or in a geocentric orbit around Earth.
  
• x = 4/20:
  Implementation/application of ideas, but credit given for effort rather than merit. Incomplete/inconclusive diagram, or argument based on retrograde/prograde motion.
  
• y = 2/20:
  Irrelevant discussion/effectively blank.
  
• z = 0/20:
  Blank.
  

Grading distribution:
Section 70158
p: 17 students
r: 5 students
t: 16 students
v: 11 students
x: 3 students
y: 2 students
z: 0 students

A sample "p" response (from student 1234):
A sample "r" response (from student 2388), with an incorrect conclusion, despite a correct diagram:
A sample "t" response (from student 7873), depicting Venus low in east horizon at sunrise:
A sample "v" response (from student 1781), using a geocentric model with phase/timing/horizon inconsistencies:

Physics midterm problem: constant speed block down ramp

Physics 205A Midterm 1, Fall Semester 2009
Cuesta College, San Luis Obispo, CA

Cf. Giambattista/Richardson/Richardson, Physics, 2/e, Comprehensive Problem 4.112

[20 points.] A Physics 205A student wants a 20 kg box to slide with constant speed down a ramp that is inclined 10° from the horizontal. The coefficient of kinetic friction between the ramp and box is 0.40. What direction (up along the ramp, or down along the ramp) and magnitude force should the student exert on the box such that it slides down the ramp with constant speed? Assume that the box has already been unstuck. Show your work and explain your reasoning.

Solution and grading rubric:

• p = 20/20:
  Correct. Resolves weight into w_x and w_y components (parallel and perpendicular to ramp, respectively). Then applies Newton's first law along the (tilted) y-direction to find normal force of ramp on box, and thus f_k = mu_k*N (pointing up along the ramp). Since f_k up along the ramp is larger than w_x down along the ramp, F_applied needs to be the difference between their magnitudes f_k - w_x.
  
• r = 16/20:
  Nearly correct, but includes minor math errors. Typically uses N = w = m*g or N = w_y = m*g/cos(10 degrees) instead of N = w_y = m*g*cos(degrees); or sets F_app = f_k only, neglecting w_x component, otherwise methodical application of Newton's first law along y- and x- direciton. May also have sines and cosines switched, calculator was used in radians mode, or spurious force/component added back in.
  
• t = 12/20:
  Nearly correct, but approach has conceptual errors, and/or major/compounded math errors. Some attempt at resolving w into components on a substantive free-body diagram, and/or methodical application of Newton's first law along (tilted) y- and x- directions. May have two errors/omissions of those described in (r).
  
• v = 8/20:
  Implementation of right ideas, but in an inconsistent, incomplete, or unorganized manner. Serious attempt at free-body diagram and application of Newton's laws.
  
• x = 4/20:
  Implementation of ideas, but credit given for effort rather than merit.
  
• y = 2/20:
  Irrelevant discussion/effectively blank.
  
• z = 0/20:
  Blank.
  

Grading distribution:
Sections 70854, 70855, 72177
p: 12 students
r: 14 students
t: 12 students
v: 26 students
x: 1 student
y: 0 students
z: 0 students

A sample of a "p" response (from student 1717):
Another sample of a "p" response (from student 7895):
A sample of an "r" response (from student 2022), where the x- and y- components of weight were switched:

Physics midterm problem: jumping frog

Physics 205A Midterm 1, fall semester 2009
Cuesta College, San Luis Obispo, CA

Cf. Giambattista/Richardson/Richardson, Physics, 2/e, Problem 3.55(b)

[20 points.] A frog jumps at an angle of 40° from the horizontal, and lands back on the level ground 0.87 s later, a distance of 4.4 m away. Solve for the x- and y-components of its initial velocity. Show your work and explain your reasoning.

Solution and grading rubric:

• p = 20/20:
  Correct. Solves for average horizontal speed from given horizontal displacement and elapsed time, this must also be the initial horizontal velocity component v_ix. Then can use the initial trajectory angle to solve for v_iy = v_ix·tan(40°). Or can use half of flight time, and v_fy = 0 at top of trajectory to find v_iy .
  
• r = 16/20:
  Nearly correct, but includes minor math errors. May have shifted a decimal place, or used tan(40°) = adjacent/opposite, or apparent miscalculation of otherwise correct equations.
  
• t = 12/20:
  Nearly correct, but approach has conceptual errors, and/or major/compounded math errors. At least has v_ix = ∆x/∆t. Garbles attempt at using kinematics to find v_iy (typically using 0.87 s as the time to travel to its highest height).
  
• v = 8/20:
  Implementation of right ideas, but in an inconsistent, incomplete, or unorganized manner. Still has a methodical approach based on kinematics and/or trigonometry. May claim that ∆x/∆t is the magnitude of the initial velocity vector, which is then broken into v_ix and v_iy components using cos(40°) and sin(40°).
  
• x = 4/20:
  Implementation of ideas, but credit given for effort rather than merit.
  
• y = 2/20:
  Irrelevant discussion/effectively blank.
  
• z = 0/20:
  Blank.

Grading distribution:
Sections 70854, 70855, 72177
p: 26 students
r: 9 students
t: 9 students
v: 9 students
x: 10 students
y: 2 students
z: 0 students

A sample of a "p" response, using the time of flight and initial velocity vector angle to solve for the magnitude of the initial velocity vector, which is then broken into x- and y- components (from student 2323):
Another "p" response, using the time of flight and the horizontal range to solve for the x-component of the initial velocity vector, and together with the initial velocity vector direction is used to find the y-component of the initial velocity vector (from student 6405):
An "r" response, but with the entire flight time used to find the y-component of the initial velocity vector (from student 1251):
Another "r" response, with a misapplication of the tangent function (from student 2051):
A sample of a "v" response, where the x-component of the initial velocity vector is used as the magnitude of the initial velocity vector (from student 9685):