20101231

Physics final exam question: induced current in loop

Physics 205B Final Exam, fall semester 2010
Cuesta College, San Luis Obispo, CA

Cf. Giambattista/Richardson/Richardson, Physics, 2/e, Multiple-Choice Question 29.4.

The current in a long wire is increasing over time. A square metal loop (of resistance R) is located below the wire. What is the direction (clockwise/counterclockwise) of the current induced in the square loop? Explain your answers using the appropriate right-hand rules, Faraday's law and Lenz's law.

Solution and grading rubric:
  • p:
    Correct. Applies RHR2 to determine direction of (increasing) B field through the loop (out of the page), which means magnetic flux out of the page increases over time, then uses Faraday's law and Lenz's law to determine that the loop's induced magnetic field must point into the page, and uses RHR3 to determine the direction (clockwise) of the induced current in the loop.
  • r:
    As (p), but argument indirectly, weakly, or only by definition supports the statement to be proven, or has minor inconsistencies or loopholes. May have direction/sign wrong in RHR2/flux/F's law/L's law/RHR3 process.
  • t:
    Nearly correct, but argument has conceptual errors, or is incomplete. Few missing pieces, but still demonstrates RHR2/flux/F's law/L's law/RHR3 process.
  • v:
    Limited relevant discussion of supporting evidence of at least some merit, but in an inconsistent or unclear manner.
  • x:
    Implementation/application of ideas, but credit given for effort rather than merit.
  • y:
    Irrelevant discussion/effectively blank.
  • z:
    Blank.

Grading distribution:
Section 70856
p: 4 students
r: 3 students
t: 3 students
v: 0 students
x: 0 students
y: 0 students
z: 0 students

A sample "p" response (from student 1234), although "force" in the second sentence should refer to "flux" instead:

20101230

Physics final exam question: telescope construction

Physics 205B Final Exam, fall semester 2010
Cuesta College, San Luis Obispo, CA

Cf. Giambattista/Richardson/Richardson, Physics, 2/e, Problem 24.49

A Physics 205B student has a set of converging lenses with focal lengths 0.50 cm, 6.0 cm, 70.0 cm, and 150 cm. Describe the two lenses that should be selected as the objective and the eyepiece to make a telescope with the largest magnifying power, and what the distance between the objective and eyepiece lenses should be. Explain your answer using equations and/or diagrams.

Solution and grading rubric:
  • p:
    Correct. Chooses longest focal length lens for objective, and shortest focal length lens for eyepiece, and the distance between the objective and eyepiece is the sum of their focal lengths. May clearly show how the objective primary focal point and eyepiece secondary focal point coincide, in lieu of stating L = fo + fe.
  • r:
    As (p), but argument indirectly, weakly, or only by definition supports the statement to be proven, or has minor inconsistencies or loopholes.
  • t:
    Nearly correct, but argument has conceptual errors, or is incomplete.
  • v:
    Limited relevant discussion of supporting evidence of at least some merit, but in an inconsistent or unclear manner.
  • x:
    Implementation/application of ideas, but credit given for effort rather than merit.
  • y:
    Irrelevant discussion/effectively blank.
  • z:
    Blank.

Grading distribution:
Section 70856
p: 8 students
r: 0 students
t: 1 student
v: 0 students
x: 0 students
y: 0 students
z: 1 student

A sample "p" response (from student 8110):

20101229

Education research: ALLS post-instruction opinion results (Cuesta College, fall semester 2010)

Student attitudes are assessed using an Astronomy Laboratory Learning Survey (ALLS), a five-point Likert scale questionnaire with demographic questions, and entry/exit evaluation questions (Patrick M. Len, in development) to Astronomy 210L students at Cuesta College, San Luis Obispo, CA. This laboratory course is a one-semester, adjunct course to Astronomy 210 lecture, and is taken primarily by students to satisfy their general education science laboratory transfer requirement.

The ALLS is administered as a pre-test on the first laboratory meeting, before any introduction/instruction took place; and as a post-test on the last laboratory meeting.

The results from the post-test opinion questions follow below. Values for the mean and standard deviations are given next to the modal response category for each question.
Cuesta College
Astronomy Laboratory Learning Survey (ALLS)
Post-instruction opinion results
Astronomy 210L fall semester 2010 sections 70178, 70186, 70200

16. Astronomy lab was (or would have been) helpful for learning in lecture.
1. Strongly disagree 1 : *
2. Disagree 3 : ***
3. Neutral 7 : *******
4. Agree 31 : ******************************* [4.0 +/- 1.9]
5. Strongly agree 16 : ****************

17. I understand more about astronomy concepts because of what I learned in lab.
1. Strongly disagree 0 :
2. Disagree 1 : *
3. Neutral 4 : ****
4. Agree 29 : ***************************** [4.3 +/- 0.7]
5. Strongly agree 24 : ************************

18. Astronomy lab was an enjoyable experience.
1. Strongly disagree 0 :
2. Disagree 1 : *
3. Neutral 3 : ***
4. Agree 23 : ***********************
5. Strongly agree 31 : ******************************* [4.4 +/- 0.7]

19. Math used in astronomy lab was difficult.
1. Strongly disagree 7 : *******
2. Disagree 14 : **************
3. Neutral 25 : ************************* [2.7 +/- 1.0]
4. Agree 11 : ***********
5. Strongly agree 1 : *

20. It was hard to understand concepts in astronomy lab.
1. Strongly disagree 9 : *********
2. Disagree 26 : ************************** [2.3 +/- 0.8]
3. Neutral 18 : ******************
4. Agree 5 : *****
5. Strongly agree 0 :

21. This course helped me see how astronomy is related to other sciences such as
geology, physics, and chemistry.
1. Strongly disagree 2 : **
2. Disagree 1 : *
3. Neutral 8 : ********
4. Agree 32 : ******************************** [4.0 +/- 0.9]
5. Strongly agree 15 : ***************

22. I asked a lot of questions in astronomy lab.
1. Strongly disagree 5 : *****
2. Disagree 20 : ********************
3. Neutral 23 : *********************** [2.7 +/- 1.0]
4. Agree 6 : ******
5. Strongly agree 4 : ****

23. I generally understood what was needed to be done in astronomy lab.
1. Strongly disagree 0 :
2. Disagree 1 : *
3. Neutral 10 : **********
4. Agree 34 : ********************************** [4.0 +/- 0.7]
5. Strongly agree 13 : *************

24. My work in astronomy lab was graded fairly.
1. Strongly disagree 0 :
2. Disagree 0 :
3. Neutral 1 : *
4. Agree 23 : ***********************
5. Strongly agree 34 : ********************************** [4.6 +/- 0.5]

25. I did a lot of explaining to other students in astronomy lab.
1. Strongly disagree 0 :
2. Disagree 7 : *******
3. Neutral 22 : ********************** [3.6 +/- 0.9]
4. Agree 19 : *******************
5. Strongly agree 10 : **********

26. I was generally confused about what was going on in astronomy lab.
1. Strongly disagree 13 : *************
2. Disagree 31 : ******************************* [2.1 +/- 0.8]
3. Neutral 12 : ************
4. Agree 1 : *
5. Strongly agree 1 : *

27. I would recommend astronomy lab to other students.
1. Strongly disagree 0 :
2. Disagree 0 :
3. Neutral 2 : **
4. Agree 28 : **************************** [4.4 +/- 0.6]
5. Strongly agree 28 : ****************************

28. Astronomy lab should only be taken in the same semester as astronomy lecture.
1. Strongly disagree 4 : ****
2. Disagree 7 : ********
3. Neutral 18 : ****************** [3.4 +/- 1.1]
4. Agree 17 : *****************
5. Strongly agree 12 : ************

29. Astronomy lab should only be taken after completing the entire semester of
astronomy lecture.
1. Strongly disagree 9 : *********
2. Disagree 23 : *********************** [2.4 +/- 1.0]
3. Neutral 19 : *******************
4. Agree 5 : *****
5. Strongly agree 2 : **

30. This course helped me feel more comfortable with the idea that many values in
science are uncertain to some degree.
1. Strongly disagree 1 : *
2. Disagree 2 : **
3. Neutral 13 : *************
4. Agree 25 : ************************* [3.9 +/- 0.9]
5. Strongly agree 13 : *************

Previous posts:

20101228

Education research: ALLS demographic results (Cuesta College, fall semester 2010)

Student attitudes are assessed using an Astronomy Laboratory Learning Survey (ALLS), a five-point Likert scale questionnaire with demographic questions, and entry/exit evaluation questions (Patrick M. Len, in development) to Astronomy 210L students at Cuesta College, San Luis Obispo, CA. This laboratory course is a one-semester, adjunct course to Astronomy 210 lecture, and is taken primarily by students to satisfy their general education science laboratory transfer requirement.

The ALLS is administered as a pre-test on the first laboratory meeting, before any introduction/instruction took place; and as a post-test on the last laboratory meeting.

The results from the pre-test demographic questions follow below. Only matched-pair results are shown, for students who were eventually able to take the post-instruction ALLS at the last laboratory meeting.
Cuesta College
Astronomy Laboratory Learning Survey (ALLS)
Demographic pre-instruction question results
Astronomy 210L fall semester 2010 sections 70178, 70186, 70200
(N = 58, matched-pairs only)

16. What is your gender?
(A) Female. [27]
(B) Male. [31]

17. Have you previously taken an astronomy lecture class?
(A) Yes. [12]
(B) No. [46]

18. Are you currently enrolled in an astronomy lecture class?
(A) Yes. [50]
(B) No. [ 8]

19. How many college science courses have you completed prior
to taking this course?
(A) None. [32]
(B) 1. [18]
(C) 2. [ 6]
(D) 3. [ 1]
(E) 4+. [ 1]

20. What is your college major (or current area(s) of interest
if undecided)? Choose as many areas of interest that apply.
(A) Business. [12]
(B) Education. [ 9]
(C) Humanities, Social Sciences, or the Arts. [32]
(D) Science, Engineering, or Architecture. [10]
(E) Other. [14]

21. Which of these college math classes have you completed
prior to taking this course? Choose as many classes that apply.
(A) Algebra. [35]
(B) Trigonometry. [ 5]
(C) Geometry. [13]
(D) Pre-calculus. [18]
(E) Calculus. [ 6]
(F) Statistics. [ 8]

Previous posts:

20101227

Education research: ALLS pre- to post-instruction attitude shifts (Cuesta College, Fall 2010)

Student attitudes are assessed using an Astronomy Laboratory Learning Survey (ALLS), a five-point Likert scale questionnaire with demographic questions, and entry/exit evaluation questions (Patrick M. Len, in development) to Astronomy 210L students at Cuesta College, San Luis Obispo, CA. This laboratory course is a one-semester, adjunct course to Astronomy 210 lecture, and is taken primarily by students to satisfy their general education science laboratory transfer requirement.

The ALLS is administered as a pre-test on the first laboratory meeting, before any introduction/instruction took place; and as a post-test on the last laboratory meeting.

The results from the pre- and post-test questions follow below. Values for the mean and standard deviations are given next to the modal response category for each question, along with a Student t-test for the probability of null hypothesis rejection, and the class-wise Hake gain. (Matched-pair Hake gains were not calculated for each student, as pre-instruction values such as "5" would result in undefined values.) For statistical purposes, blank entries were treated as "3. Neutral," and multiply-circled entries such as "12," "23," "34," and "45" were treated as "1," "2," "4," and "5" respectively.
Cuesta College
Astronomy Laboratory Learning Survey (ALLS)
Pre- and post-instruction results
Astronomy 210L Fall 2010 sections 70178, 70186, 70200

1. I am interested in using a telescope or binoculars for astronomy.
Pre-instruction
1. Strongly disagree 3 : ***
2. Disagree 11 : ***********
3. Neutral 12 : ************
4. Agree 35 : *********************************** [3.6 +/- 1.1]
5. Strongly agree 16 : ****************

Post-instruction
1. Strongly disagree 0 :
2. Disagree 0 :
3. Neutral 12 : ************
4. Agree 27 : *************************** [4.1 +/- 0.7]
5. Strongly agree 19 : *******************

Student t-test p = 0.0050 (t = -2.86, sd = 0.949, dof = 133)
Class-wise <g> = +0.35

2. Astronomy has little relation to what I experience in the real world.
Pre-instruction
1. Strongly disagree 11 : ***********
2. Disagree 36 : ************************************ [2.4 +/- 0.9]
3. Neutral 20 : ********************
4. Agree 7 : *******
5. Strongly agree 2 : **

Post-instruction
1. Strongly disagree 9 : *********
2. Disagree 28 : **************************** [2.3 +/- 0.9]
3. Neutral 16 : ****************
4. Agree 3 : ***
5. Strongly agree 2 : **

Student t-test p = 0.74 (t = 0.332, sd = 0.932, dof = 132)
Class-wise <g> = -0.02

3. I know where and how to look up astronomy information.
Pre-instruction
1. Strongly disagree 8 : ********
2. Disagree 25 : *************************
3. Neutral 25 : ************************* [2.7 +/- 1.0]
4. Agree 16 : ****************
5. Strongly agree 2 : **

Post-instruction
1. Strongly disagree 0 :
2. Disagree 1 : *
3. Neutral 7 : *******
4. Agree 30 : ****************************** [4.2 +/- 0.7]
5. Strongly agree 20 : ********************

Student t-test p < 0.0001 (t = -9.47, sd = 0.888, dof = 132)
Class-wise <g> = +0.64

4. I know where and how to find objects in the night sky.
Pre-instruction
1. Strongly disagree 11 : ***********
2. Disagree 25 : *************************
3. Neutral 21 : ********************* [2.7 +/- 1.1]
4. Agree 16 : ****************
5. Strongly agree 4 : ****

Post-instruction
1. Strongly disagree 0 :
2. Disagree 1 : *
3. Neutral 9 : *********
4. Agree 37 : ************************************ [4.0 +/- 0.6]
5. Strongly agree 11 : ******

Student t-test p < 0.0001 (t = -7.93, sd = 0.942, dof = 133)
Class-wise <g> = +0.57

5. I am interested in news that is related to astronomy.
Pre-instruction
1. Strongly disagree 0 :
2. Disagree 3 : ***
3. Neutral 13 : *************
4. Agree 43 : ******************************************* [4.0 +/- 0.7]
5. Strongly agree 17 : *****************

Post-instruction
1. Strongly disagree 0 :
2. Disagree 3 : ***
3. Neutral 12 : ************
4. Agree 24 : ************************ [4.0 +/- 0.9]
5. Strongly agree 19 : *******************

Student t-test p = 0.76 (t = 0.311, sd = 0.802, dof = 132)
Class-wise <g> = +0.04

6. I often ask myself questions related to astronomy.
Pre-instruction
1. Strongly disagree 2 : **
2. Disagree 10 : **********
3. Neutral 27 : ***************************
4. Agree 28 : **************************** [3.4 +/- 1.0]
5. Strongly agree 10 : **********

Post-instruction
1. Strongly disagree 2 : **
2. Disagree 8 : ********
3. Neutral 14 : ************** [3.6 +/- 1.1]
4. Agree 23 : ***********************
5. Strongly agree 11 : ***********

Student t-test p = 0.47 (t = -0.727, sd = 1.01, dof = 133)
Class-wise <g> = +0.08

7. I am comfortable using a calculator to make complex calculations.
Pre-instruction
1. Strongly disagree 9 : *********
2. Disagree 4 : ****
3. Neutral 18 : ******************
4. Agree 33 : ********************************* [3.5 +/- 1.2]
5. Strongly agree 13 : *************

Post-instruction
1. Strongly disagree 2 : **
2. Disagree 3 : ***
3. Neutral 13 : *************
4. Agree 24 : ************************ [3.8 +/- 1.0]
5. Strongly agree 16 : ****************

Student t-test p = 0.062 (t = -1.88, sd = 1.11, dof = 133)
Class-wise <g> = +0.24

8. I can make sense of equations and scientific notation numbers.
Pre-instruction
1. Strongly disagree 4 : ****
2. Disagree 5 : *****
3. Neutral 21 : *********************
4. Agree 36 : ************************************ [3.6 +/- 1.0]
5. Strongly agree 10 : **********

Post-instruction
1. Strongly disagree 0 :
2. Disagree 5 : *****
3. Neutral 11 : ***********
4. Agree 30 : ****************************** [3.8 +/- 0.9]
5. Strongly agree 12 : ************

Student t-test p = 0.088 (t = -1.72, sd = 0.930, dof = 132)
Class-wise <g> = +0.20

9. I prefer to work independently rather than in groups.
Pre-instruction
1. Strongly disagree 7 : *******
2. Disagree 20 : ********************
3. Neutral 34 : ********************************** [2.9 +/- 1.1]
4. Agree 4 : ****
5. Strongly agree 12 : ************

Post-instruction
1. Strongly disagree 9 : *********
2. Disagree 17 : *****************
3. Neutral 19 : ******************* [2.7 +/- 1.2]
4. Agree 6 : ******
5. Strongly agree 7 : *******

Student t-test p = 0.38 (t = 0.887, sd = 1.17, dof = 133)
Class-wise <g> = -0.09

10. I can understand difficult concepts better if I am able to explain them
to others.
Pre-instruction
1. Strongly disagree 2 : **
2. Disagree 14 : **************
3. Neutral 23 : ***********************
4. Agree 26 : ************************** [3.4 +/- 1.0]
5. Strongly agree 12 : ************

Post-instruction
1. Strongly disagree 1 : *
2. Disagree 4 : ****
3. Neutral 11 : ***********
4. Agree 28 : **************************** [3.9 +/- 0.9]
5. Strongly agree 14 : **************

Student t-test p = 0.011 (t = -2.58, sd = 0.995, dof = 133)
Class-wise <g> = +0.28

11. I can understand difficult concepts better if I am able to ask lots of
questions.
Pre-instruction
1. Strongly disagree 0 :
2. Disagree 4 : ****
3. Neutral 17 : ************
4. Agree 40 : **************************************** [3.9 +/- 0.8]
5. Strongly agree 15 : ***************

Post-instruction
1. Strongly disagree 0 :
2. Disagree 4 : ****
3. Neutral 10 : **********
4. Agree 29 : ***************************** [3.9 +/- 0.8]
5. Strongly agree 15 : ***************

Student t-test p = 0.57 (t = 0.562, sd = 0.814, dof = 132)
Class-wise <g> = +0.07

12. Knowledge in astronomy consists of many pieces of information each of which
applies primarily to a specific situation.
Pre-instruction
1. Strongly disagree 0 :
2. Disagree 6 : ******
3. Neutral 44 : ******************************************** [3.3 +/- 0.7]
4. Agree 19 : *******************
5. Strongly agree 5 : *****

Post-instruction
1. Strongly disagree 0 :
2. Disagree 2 : **
3. Neutral 28 : ****************************
4. Agree 19 : ******************* [3.6 +/- 0.8]
5. Strongly agree 9 : *********

Student t-test p = 0.028 (t = -2.22, sd = 0.753, dof = 130)
Class-wise <g>> = +0.17

13. I am good at math.
Pre-instruction
1. Strongly disagree 9 : *********
2. Disagree 13 : *************
3. Neutral 17 : *****************
4. Agree 33 : ********************************* [3.2 +/- 1.1]
5. Strongly agree 5 : *****

Post-instruction
1. Strongly disagree 6 : ******
2. Disagree 12 : ************
3. Neutral 14 : ************** [3.2 +/- 1.2]
4. Agree 19 : *******************
5. Strongly agree 7 : *******

Student t-test p = 1.00 (t = 0.00331, sd = 1.17, dof = 133)
Class-wise <g> = 0

14. I am good at science.
Pre-instruction
1. Strongly disagree 3 : ***
2. Disagree 11 : ***********
3. Neutral 22 : ********************** [3.4 +/- 1.0]
4. Agree 35 : ***********************************
5. Strongly agree 6 : ******

Post-instruction
1. Strongly disagree 3 : ***
2. Disagree 6 : ******
3. Neutral 23 : *********************** [3.3 +/- 1.0]
4. Agree 20 : ********************
5. Strongly agree 6 : ******

Student t-test p = 0.79 (t = 0.265, sd = 0.971, dof = 133)
Class-wise <g> = -0.03

15. This course will be/was difficult for me.
Pre-instruction
1. Strongly disagree 2 : **
2. Disagree 29 : *****************************
3. Neutral 30 : ****************************** [2.8 +/- 0.9]
4. Agree 13 : *************
5. Strongly agree 3 : ***

Post-instruction
1. Strongly disagree 9 : *********
2. Disagree 19 : ******************* [2.5 +/- 1.0]
3. Neutral 24 : ************************
4. Agree 4 : ****
5. Strongly agree 2 : **

Student t-test p = 0.048 (t = 1.99, sd = 0.917, dof = 133)
Class-wise <g> = -0.15

A statistically significant (p < 0.05) positive shift was observed for the interest in using telescopes/binoculars in astronomy (question 1); there was a statistically insignificant positive shift in Spring 2010, and notably a statistically significant (p < 0.05) negative shift in Fall 2009!

Also no statistically significant (p > 0.05) shifts were observed for relating astronomy to personal experience (question 2), interest in astronomy-related news (question 5), pondering astronomy-related questions (question 6), self-efficacy in use of calculators and math in astronomy (questions 7 and 8), individual/group learning habits (questions 9 and 11), and self-efficacy in math/science (questions 13 and 14).

However, there are statistically significant (p < 0.05) gains in being able to find astronomy-related news/information (question 3), finding night sky objects (question 4), understanding concepts better by explaining (question 10), disconnectedness in astronomy concepts (question 12), and rating the expected/experience difficulty of this course (question 15). The first two of these positive self-reported shifts correlate well with two of the student learning outcomes for this course:
  • Keep abreast of present-day discoveries and developments in astronomy (current events).
  • Construct and use devices to measure locations and sizes on the celestial sphere (observational astronomy).
(For completeness, the remaining four student learning outcomes are listed below, and are measured primarily through grade-related assessment):
  • Apply laws of spectroscopy and gravitation to remotely determine properties of satellites, planets, and stars (astronometry).
  • Develop and test physical models of the properties of solar system bodies (planetology).
  • Collect data, evaluate the data using error analysis, draw conclusions from the data.
  • Explain the information in a laboratory report.
Previous posts:

20101226

Education research: post-instruction feedback on laboratory learning (Cuesta College, Physics 205B, fall semester 2010)

Cuesta College students taking Physics 205B (college physics, algebra-based) at Cuesta College, San Luis Obispo, CA take a mandatory adjunct laboratory. Instead of a conventional set of step-by-step equipment set-up instructions, students are given a specific task to set up, complete and document. For example:
  1. Construct a circuit consisting of a single 9-V battery, and as many Xmas light bulbs (and connectors) as necessary such that there are bulbs with at least three different brightness levels.
  2. Make the appropriate measurements to determine the current and voltage drop of each different brightness bulb when on, in order to calculate the resistance and power dissipated for each unique brightness light bulb (with significant figures).
  3. Discuss how your measurements/calculations demonstrate that there are light bulbs with three different power levels.
(Note that the above task follows an earlier lab where students were not told how to use multimeters, but instructed to tinker and determine their proper handling and use in simple measurements.)

During the last week of instruction, students were given the opportunity to evaluate the laboratory components of the course in an online "Physics Laboratory Learning Survey" hosted by SurveyMonkey.com.

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 certain sections were randomly scrambled for each student.
Physics Laboratory Learning Survey
Cuesta College
Physics 205B fall semester 2010 section 70856
(N = 11)

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


II.1 Which of the following best characterizes your
preparation/involvement for lab? Mark all that apply.
Read the directions/review concepts...

1. while doing the lab. 8 : ********
2. immediately before starting the lab. 9 : *********
3. the night before the lab. 5 : *****
4. a day (or more) before the lab. 2 : **

II.2 How often did a lab build upon a previous lecture experience?
1. Never 0 :
2. Not much 0 :
3. Sometimes 1 : *
4. Often 3 : ***
5. Always 7 : ******* [4.5 +/- 0.7]

II.3 How often did a lab build upon a previous lab experience?
1. Never 0 :
2. Not much 1 : *
3. Sometimes 5 : ***** [3.5 +/- 0.9]
4. Often 3 : ***
5. Always 2 : **


III. Rate the level of your understanding/comprehension for a typical lab.

III.1 Understanding of concepts before coming to lab.
1. None 0 :
2. Very little 0 :
3. Neutral 7 : *******
4. Much 4 : **** [3.4 +/- 0.5]
5. Complete 0 :

III.2 Understanding of concepts after pre-lab discussion, before starting work.
1. None 0 :
2. Very little 0 :
3. Neutral 5 : *****
4. Much 5 : ***** [3.6 +/- 0.6]
5. Complete 1 : *

III.3 Understanding of concepts after completing in-lab work.
1. None 0 :
2. Very little 0 :
3. Neutral 0 :
4. Much 7 : ******* [4.4 +/- 0.5]
5. Complete 4 : ****

III.4 Understanding of concepts after completing lab report.
1. None 0 :
2. Very little 0 :
3. Neutral 1 : *
4. Much 5 : ***** [4.4 +/- 0.6]
5. Complete 5 : *****

III.5 Comprehension of overall lab procedure/instructions.
1. None 0 :
2. Very little 0 :
3. Neutral 2 : **
4. Much 3 : *** [4.4 +/- 0.8]
5. Complete 6 : ******

III.6 Comprehension of overall lab purpose.
1. None 0 :
2. Very little 0 :
3. Neutral 2 : **
4. Much 3 : *** [4.4 +/- 0.8]
5. Complete 6 : ******


IV. Typically a lab would help me understand the concepts.
1. Strongly disagree 0 :
2. Disagree 2 : **
3. Some 2 : **
4. Agree 5 : ***** [3.6 +/- 1.0]
5. Strongly agree 2 : **


V.1 How much time did you typically spend preparing/studying
before the start of lab (including work on pre-lab assignments)?
1. 15 minutes or less 4 : ****
2. 30 minutes 6 : ******
3. 1 hour 1 : *
4. 2 hours 0 :
5. 3 hours or more 0 :

V.2 How much time did you typically spend working on lab reports
(after completing in-lab work)?
1. 15 minutes or less 0 :
2. 30 minutes 2 : **
3. 1 hour 5 : *****
4. 2 hours 4 : ****
5. 3 hours or more 0 :


VI. (Optional.) Please type in any comments you may have regarding
the laboratory portion of this class.
"The labs were fun, but I never understood the reflection part of it."

"The 205A lab was just a waste of time but this lab was actually helped me understand the material better ( To be honest I didn't expect that to help me at all)"

"..."

"I feel we did not go over the concepts enough in lecture before doing the labs."
Previous post:

20101224

Education research: post-instruction feedback on flashcards, reading assignments, homework reports (Cuesta College, Physics 205B, fall semester 2010)

Cuesta College students taking Physics 205B (college physics, algebra-based, mandatory adjunct laboratory) at Cuesta College, San Luis Obispo, CA use flashcards to engage in peer-interaction ("think-(pair)-share") discussion questions during lecture, and complete weekly online reading assignments (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.

During the last week of instruction, students were given the opportunity to evaluate the instructional components of the course, and the use of flashcards, online reading assignments, and online homework reports (Matthew L. Trawick, The Physics Teacher, vol. 48, no. 2, p. 118) 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, III and V were randomly scrambled for each student.
Learning Resource Survey
Cuesta College
Physics 205B fall semester 2010 section 70856
(N = 11)

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 0 :
3. Neutral 1 : *
4. Agree 4 : ****
5. Strongly agree 6 : ****** [4.5 +/- 0.7]

II.2 Doing unassigned flashcard questions.
1. Strongly disagree 2 : **
2. Disagree 0 :
3. Neutral 0 :
4. Agree 6 : ****** [3.7 +/- 1.4]
5. Strongly agree 3 : ***

II.3 Using flashcards to participate in class.
1. Strongly disagree 0 :
2. Disagree 0 :
3. Neutral 0 :
4. Agree 5 : *****
5. Strongly agree 6 : ****** [4.5 +/- 0.5]

II.4 Reading the textbook.
1. Strongly disagree 2 : **
2. Disagree 1 : *
3. Neutral 4 : **** [2.9 +/- 1.2]
4. Agree 4 : ****
5. Strongly agree 0 :

II.5 Demonstrations/videos in class.
1. Strongly disagree 0 :
2. Disagree 3 : ***
3. Neutral 1 : *
4. Agree 3 : ***
5. Strongly agree 4 : **** [3.7 +/- 1.2]

II.6 Interacting with other students during class.
1. Strongly disagree 0 :
2. Disagree 1 : *
3. Neutral 1 : *
4. Agree 6 : ****** [4.0 +/- 0.9]
5. Strongly agree 3 : ***

II.7 Instructor follow-up on difficult online homework report problems.
1. Strongly disagree 0 :
2. Disagree 0 :
3. Neutral 1 : *
4. Agree 2 : **
5. Strongly agree 8 : ******** [4.6 +/- 0.6]

II.8 Online reading assignments.
1. Strongly disagree 0 :
2. Disagree 3 : ***
3. Neutral 1 : *
4. Agree 6 : ****** [3.5 +/- 1.0]
5. Strongly agree 1 : *

II.9 Online homework reports.
1. Strongly disagree 0 :
2. Disagree 1 : *
3. Neutral 2 : **
4. Agree 4 : **** [4.0 +/- 1.0]
5. Strongly agree 4 : ****

II.10 Interacting with other students outside of class.
1. Strongly disagree 0 :
2. Disagree 2 : **
3. Neutral 4 : **** [3.5 +/- 1.0]
4. Agree 3 : ***
5. Strongly agree 2 : **

II.11 Group problem solving sessions (on whiteboards).
1. Strongly disagree 1 : *
2. Disagree 0 :
3. Neutral 2 : **
4. Agree 4 : **** [3.9 +/- 1.2]
5. Strongly agree 4 : ****

II.12 Group concept mapping (on whiteboards).
1. Strongly disagree 1 : *
2. Disagree 4 : ****
3. Neutral 4 : **** [2.8 +/- 1.2]
4. Agree 0 :
5. Strongly agree 2 : **

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

III.1 I like using flashcards.
1. Strongly disagree 0 :
2. Disagree 0 :
3. Neutral 1 : *
4. Agree 6 : ****** [4.3 +/- 0.6]
5. Strongly agree 4 : ****

III.2 Flashcards helped me understand lectures better.
1. Strongly disagree 0 :
2. Disagree 0 :
3. Neutral 0 :
4. Agree 6 : ****** [4.5 +/- 0.5]
5. Strongly agree 5 : *****

III.3 I would recommend using flashcards in future semesters of Physics 205B.
1. Strongly disagree 0 :
2. Disagree 0 :
3. Neutral 0 :
4. Agree 6 : ****** [4.5 +/- 0.5]
5. Strongly agree 5 : *****

III.4 I will avoid other classes using flashcards in future semesters.
1. Strongly disagree 5 : *****
2. Disagree 5 : ***** [1.6 +/- 1.5]
3. Neutral 1 : *
4. Agree 0 :
5. Strongly agree 0 :

III.5 Flashcards were a positive experience.
1. Strongly disagree 0 :
2. Disagree 0 :
3. Neutral 1 : *
4. Agree 6 : ****** [4.3 +/- 0.6]
5. Strongly agree 4 : ****

III.6 Too much time in class was spent using flashcards.
1. Strongly disagree 3 : ***
2. Disagree 5 : ***** [2.0 +/- 1.0]
3. Neutral 3 : ***
4. Agree 0 :
5. Strongly agree 0 :

III.7 Too many flashcard questions were asked.
1. Strongly disagree 4 : ****
2. Disagree 5 : ***** [1.8 +/- 1.3]
3. Neutral 2 : **
4. Agree 0 :
5. Strongly agree 0 :

III.8 Using flashcards was difficult.
1. Strongly disagree 7 : ******* [1.5 +/- 2.1]
2. Disagree 3 : ***
3. Neutral 1 : *
4. Agree 0 :
5. Strongly agree 0 :

IV. (Optional.) Please type in any comments you may have regarding
the use of flashcards in Physics 205B.
"one answer could be, 'I would know the answer, and know how to do it, but I ran out of time.'"

"It helped us apply something that we had just learned instead of having to gruel over it later for homework."

"I think I little bit too much time is given to come up with answers but flashcard questions are helpfull to formulate questions to ask in class. Otherwise I had a hard time remembering what i was confused about on the homework."

"Flash cards helped me study the most for quizzes and tests."

"When doing flashcard questions which have multiple scenarios given by which one you circle, I would have liked to go through all scenarios for each problem that we did. I felt that when we did the questions in class, we would do the easiest scanarios and skip the harder ones."

"I believe there should be more questions in each sections. they were the most helpful thing during this class."

"An answer key to the flashcard questions would be helpful for the quizzes"
V. Answer the following statements which may or may not describe 
your beliefs about working on the online reading assignments
in this class.

V.1 Online reading assignments were a positive experience.
1. Strongly disagree 1 : *
2. Disagree 0 :
3. Neutral 5 : ***** [3.3 +/- 0.9]
4. Agree 5 : *****
5. Strongly agree 0 :

V.2 I like working on the online reading assignments.
1. Strongly disagree 1 : *
2. Disagree 4 : ****
3. Neutral 5 : ***** [2.6 +/- 1.0]
4. Agree 0 :
5. Strongly agree 1 : *

V.3 Too much time outside of class was spent working on online reading assignments.
1. Strongly disagree 1 : *
2. Disagree 5 : ***** [2.5 +/- 0.8]
3. Neutral 4 : ****
4. Agree 1 : *
5. Strongly agree 0 :

V.4 I will avoid other classes using online reading assignments in future semesters.
1. Strongly disagree 2 : **
2. Disagree 6 : ****** [2.2 +/- 0.9]
3. Neutral 2 : **
4. Agree 1 : *
5. Strongly agree 0 :

V.5 Online reading assignments helped me understand lectures better.
1. Strongly disagree 0 :
2. Disagree 2 : **
3. Neutral 2 : **
4. Agree 5 : ***** [3.6 +/- 1.0]
5. Strongly agree 2 : **

V.6 Too many online reading assignment questions were asked.
1. Strongly disagree 1 : *
2. Disagree 5 : ***** [2.6 +/- 1.0]
3. Neutral 2 : **
4. Agree 3 : ***
5. Strongly agree 0 :

V.7 I would recommend using online reading assignments in future semesters of this class.
1. Strongly disagree 0 :
2. Disagree 2 : **
3. Neutral 3 : ***
4. Agree 5 : ***** [3.6 +/- 0.9]
5. Strongly agree 1 : *

V.8 Completing the online reading assignments was difficult.
1. Strongly disagree 1 : *
2. Disagree 3 : ***
3. Neutral 6 : ****** [2.6 +/- 0.8]
4. Agree 1 : *
5. Strongly agree 0 :

VI. (Optional.) Please type in any comments you may have regarding
the use of online home assignments in Physics 205B.
The following are all of the student responses to this question, verbatim and unedited.
"a list of what to skip and what to read in a chapter"

"The actually reading assignments themselves were very easy. The hard part was remembering to do them."

"They weren't too hard, but also not that helpfull."

"A lot of the time the reading was too confusing without having lecture first."

"I found that online reading assignments were not very helpful. We would go over things in the reading assignments that werent even covered in lecture. I felt it easier to not read the book and just go off the information taught during class. Also online reading assignments were always different in regards to whether they were on the material we aready covered or what came next so I never knew what to read before doing the assigments. Also I think if you are to continue to do the reading assignments, if it looks as though the class was confused on a specific question, go over that answer right away instead of saying 'we will get to that in lecture' because I could never tell if the question was answered in lecture or not or if you continue to talk about the answers in lecture make sure to address that that was the answer to this specific reading question."

"Being ahead of the class is always helpful."
VII. Answer the following statements which may or may not describe 
your beliefs about working on the online homework reports
in this class.

VII.1 Online homework reports were a positive experience.
1. Strongly disagree 0 :
2. Disagree 1 : *
3. Neutral 2 : **
4. Agree 5 : ***** [3.9 +/- 0.9]
5. Strongly agree 3 : ***

VII.2 Instructor follow-up on difficult online homework report questions was valuable.
1. Strongly disagree 0 :
2. Disagree 0 :
3. Neutral 0 :
4. Agree 3 : ***
5. Strongly agree 8 : ******** [4.7 +/- 0.4]

VII.3 Online homework reports motivated me to complete (or try to complete) problems on my own before coming to class.
1. Strongly disagree 1 : *
2. Disagree 3 : *** [3.4 +/- 1.4]
3. Neutral 1 : *
4. Agree 3 : ***
5. Strongly agree 3 : ***

VII.4 Too many online homework report questions were asked.
1. Strongly disagree 1 : *
2. Disagree 6 : ****** [2.5 +/- 0.9]
3. Neutral 2 : **
4. Agree 2 : **
5. Strongly agree 0 :

VII.5 I would recommend using online homework reports in future semesters of this class.
1. Strongly disagree 0 :
2. Disagree 2 : **
3. Neutral 1 : *
4. Agree 2 : **
5. Strongly agree 6 : ****** [4.1 +/- 1.2]

VIII. (Optional.) Please type in any comments you may have regarding
the use of online home assignments in Physics 205B.
The following are all of the student responses to this question, verbatim and unedited.
"better thank clickers?"

"Its easy to forget to do your homework when the means to do it is on the computer ."

"The idea is a good one, but there is no accountability if you don't do the assignment."

"Sometimes the homework problems were helpful but we didn't really have enough class time to go over the problems. Maybe try making time for an example before the homework so that there are less questions after the online assignment???"

"hw is good practice"

"Some questions I had difficulties on were often not on the homework report. it would be helpful to ask if there were any problems not on the report that we may have needed help on."

"I liked the whole method of the class, and how the instructor kept track of every student's steps."

"Solving difficult problems and flash card questions was the best."

"It was harder to motivate myself rather than if we had to turn the homework in but it was nice..."

"I liked it overall"


Previous post:

20101223

Education research: post- feedback on think-pair-share attitudes (Astronomy 210, Cuesta College, Fall Semester 2010)

Cuesta College students taking Astronomy 210 (introductory astronomy) at Cuesta College, San Luis Obispo, CA used flashcards to engage in peer-interaction ("think-pair-share") discussion questions during lecture.

During the last week of instruction, students were given the opportunity to evaluate the use of clickers in implementing peer-instruction in an online "Think-Pair-Share Survey" hosted by SurveyMonkey.com.

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.

Cuesta College
Astronomy 210 Fall Semester 2010 sections 70158, 70160
(N = 64)

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


II. Recall that for this semester that flashcards are used in a think-pair-share
system, where students think and answer individually, and if there is a lack of
consensus, then students pair off and share explanations with each other before
answering again. Answer the following statements which may or may not describe
your beliefs about think-pair-share in this class.

II.1 I feel comfortable engaging with think-pair-share with other students.
1. Strongly disagree 0 :
2. Disagree 6 : ******
3. Neutral 10 : **********
4. Agree 35 : *********************************** [3.8 +/- 0.8]
5. Strongly agree 11 : ***********

II.2 I explain more often than I listen to other students during
think-pair-share.
1. Strongly disagree 0 :
2. Disagree 14 : **************
3. Neutral 33 : ********************************* [3.0 +/- 0.7]
4. Agree 15 : ***************
5. Strongly agree 0 :

II.3 I change answers more often than I keep the same answer after
think-pair-share.
1. Strongly disagree 0 :
2. Disagree 17 : *****************
3. Neutral 27 : *************************** [3.0 +/- 0.8]
4. Agree 16 : ****************
5. Strongly agree 2 : **

III. (Optional.) Please type in any comments you may have regarding the use of
think-pair-share flashcard use in this class.
The following are all of the student responses to this question, verbatim and unedited (with a few editorial context clarifications in [brackets]).
"I think you should let the students make the questions and ask their classmates"

"it seems to work fairly well for our setting."

"I think it's a pretty good way of gaining more understanding and being able to come up with an explanation, to ensure 'you' actually know why."

"Its ok"

"flash card questions are fine, but i really wish our tests/quizzes were visibly graded when handed back to us"

"great job!"

"I liked it because usually another students explanation of the answer is easier to understand and makes more sense to "

"I think flashcards are a good idea, it helps me better undertand the topics we cover in class"

"Is good."

"I think think-pair-share is beneficial because it is useful to learn from your peers"

"Hi :)"

"The think-pair-share flashcard use in class is very helpful also, it is fun to quiz yourself."

"its a great technique for students an many schools should use it more often"

"I didn't find the use of think-pair-share to be very beneficial to me in this class. I rarely had someone that could explain their answer to me in a way to make me change my answer, or to help me come to a decision if I was unclear."

"Its cool to have different insights on subjects. I like being able to discuise"

"I think the idea is great. I really appreciate the chance to explain it to somebody else because if I can do that it means I really know it. I think the idea would be even better if all the people who were in class said something during this time. Quite a few times, I am in a group and I have to do this, and I am the only one who talks, so I just assume that since nobody proved me wrong my answer must be right."

"I think the think-pair-share flashcard system is great, although, it is lacking something very important. Once we are finished sharing and are answering for the second time (actually, even if we only answer once) as a student I need to here the answer from you, the instructor. Even if my partner during the flashcard activities is right and explains it, I am speaking from a student in your class, I would like you to clearly state the correct answer and give a thorough explination about why that is the correct choice."

"I think it's a good way to learn because you get to learn it another way that may help you mote than the way the instructor did????"

"I think it's a really good way to find out where the class is for certain topics and allows people to discuss and really talk things out."

"They are a good way to figure out the answer as a class and a good change of pace from the lecture"

"I really enjoy doing think-pair-share because I am able to learn more than I would by just sitting listening to a lecture."

"I like the think pair share method. I love being able to hear the explanations that other students have. A lot of the time they explain it in simple terms ;3"

"I really learned a lot from listening to others explain as well as the teacher."

"I thought it was a great way of letting everyone think about concepts for themselves."

"I think this is a good way to learn but I think if the teacher were also to participate and explain each flashcard question afterward it would help a lot"

"Flashcard questions are a good tool. Keep using them P~DAWG."

"i think it is a good system. very helpful"

"I think its a pretty good system... a bit time consuming though"

"I like it because If you know you have the correct answer you can help other students also get the right answer and if you are uncertain you can get help from your fellow students when they are willing to share."

"If Im following along with lecture, which I usually am when I am present, I can answer most flashcard questions."

"I'm neutral for the second one b/c how i feel depends on who i am engaging with."

"Very useful. When you can explain in your own words, or you get explained the point by a peer, it is easier to grasp the material."

"I think its a good idea, but it would be nice if we went through all of the falsh card questions"

"I liked them except I wish that all correct answers were available to the students before the quizzes and tests."

"Good system, but I wish the teacher would explain the answers more than relying on other students to do it becaus a lot of the time nobody around me knows the answer."

"i wish he would go over the answer more"

"I enjoy think-pair-share because it gives me an opportunity to engage with the people around me and it either reinforces or makes me rethink my answers"

"I like using flashcards, if I know I'm right, I like convincing other people. If I am unsure, it is helpful to listen to the explanation of another student instead of just getting it wrong. It helps me remember."

"I think it is helpful but i still usually chose E because i rarely know how to explain it."

"they're grrrrrreat!"

"Time to print out a few new ones... Some are falling apart!"

"It often confuses me more. I have my own idea for the answer and they might have a different point, which gives me conflicted feelings and I'm forced to choose 'I'm lost.'"

"I think the flashcards are a great learning style"

"I think it's good."

"i think it is a helpful tool because sometimes its easier to understand from someone else."

"The use of think-pair-share flashcards is definitely beneficial because it enables the student to think for themselves and converse with other students to figure out the answwr instead of being given it."

"i like it even though its common for both me and the people i am talking to to have guessed at the answer."

"I like being able to discuss the answers with different classmates so i can get an understanding on the answer, but sometimes I feel that I don't get very good answers the questions and its hard to know why the answer is right"

"i like the thought of answering individually and if i get it wrong then seeing what everyone else got"

"I like this system because students can usually explain an outcome or event in ways that we can better understand."

"Using flashcards has helped me personally, and I would recommend this instruction technique be used for future semesters."

"Think-pair-share is usually helpful. Sometimes it is confusing when people are arguing their answers, but it is always eventually explained."

"I really like this method. We not only get to see someone elses point of view of why you may be wrong but also we get to know our classmates a little better."

"The flashcard questions help me for quizzes.. but i can never answer them in class"
Previous posts:

20101222

Education research: MPEX pre- and post-instruction results (Cuesta College, Fall Semester 2010)

The Maryland Physics Expectations survey (MPEX, Redish, Saul, and Steinberg, 1998) was administered to Cuesta College Physics 205B (college physics, algebra-based, mandatory adjunct laboratory) students at Cuesta College, San Luis Obispo, CA. The MPEX was given during the first week of the semester, and then on the last week of the semester, to quantify student attitudes, beliefs, and assumptions about physics using six question categories, rating responses as either favorable or unfavorable towards:
  1. Independence--beliefs about learning physics--whether it means receiving information or involves an active process of reconstructing one's own understanding;
  2. Coherence--beliefs about the structure of physics knowledge--as a collection of isolated pieces or as a single coherent system;
  3. Concepts--beliefs about the content of physics knowledge--as formulas or as concepts that underlie the formulas;
  4. Reality Link--beliefs about the connection between physics and reality--whether physics is unrelated to experiences outside the classroom or whether it is useful to think about them together;
  5. Math Link--beliefs about the role of mathematics in learning physics--whether the mathematical formalism is used as a way of representing information about physical phenomena or mathematics is just used to calculate numbers;
  6. Effort--beliefs about the kind of activities and work necessary to make sense out of physics--whether they expect to think carefully and evaluate what they are doing based on available materials and feedback or not.
Cuesta College
Physics 205B Fall Semester 2010 section 70856
San Luis Obispo, CA campus
(N = 11, matched pairs,
excluding negative informed consent form responses)

Percentage of favorable:unfavorable responses
Overall Indep. Coher. Concept Real. Math Effort
Initial 61:22 41:24 56:25 49:29 91:05 62:22 75:09
Final 53:26 35:27 55:18 47:36 77:11 47:27 49:20
Caution is advised in interpreting these results due to the extremely small number of students in this section.

Previous posts:

20101221

Education research: ECCE statistics (fall semester 2010)

Students at Cuesta College (San Luis Obispo, CA) were administered a shortened version (22 out of 45 questions) of the Electric Circuit Concept Evaluation (David Sokoloff, University of Oregon) during the first and the last week of instruction. Physics 205B is the second semester of an algebra-based introductory general physics course covering optics, electromagnetism, and modern physics, with a mandatory adjunct laboratory component.

The pre- to post-test gain for this semester at Cuesta College is:
Physics 205B Fall Semester 2010 section 70856
<initial%> = 39% +/- 13% (N = 13)
<final%> = 44% +/- 14% (N = 11)
<g> = 0.06 +/- 0.26 (matched-pairs); 0.10 (class-wise)

Caution is advised in interpreting these results due to the extremely small number of students in this section.

20101220

Physics quiz question: comparing light speeds

Physics 205B Quiz 7, Fall Semester 2010
Cuesta College, San Luis Obispo, CA

Cf. Giambattista/Richardson/Richardson, Physics, 2/e, Problem 26.3.

A Physics 205B is moving at a constant velocity to the right. Two lights are simultaneously trigged to flash (in the rest frame of the lights) when student is midway between them. According to the Physics 205B student, the speed of the flash from the right light is __________ the flash from the left light.
(A) faster than.
(B) slower than.
(C) the same as.
(D) (Not enough information is given.)

Correct answer: (C)

From Einstein's second postulate of special relativity, the speed of light is invariant and independent of the relative motion of the observer and source.

Student responses
Section 70856
(A) : 3 students
(B) : 0 students
(C) : 8 students
(D) : 0 students

Success level: 72%
Discrimination index (Aubrecht & Aubrecht, 1983): 0.33

20101219

Physics quiz question: time dilated pulse

Physics 205B Quiz 7, Fall Semester 2010
Cuesta College, San Luis Obispo, CA

Cf. Giambattista/Richardson/Richardson, Physics, 2/e, Multiple-Choice Question 26.5, Problem 26.5.

A Physics 205B student has a resting pulse of 1 second per beat. She then takes a ride aboard a spacecraft traveling at a constant velocity of 0.100c away from Earth. While the spacecraft is moving, the resting pulse of the Physics 205B student is __________ 1 second per beat, according to Earth observers.
(A) longer than.
(B) shorter than.
(C) exactly equal to.
(D) (Not enough information is given.)

Correct answer: (A)

The relevant time interval is the pulse of the Physics 205B student. The proper time interval delta(t_0) for her pulse is 1 second, as measured in her own reference frame (the spacecraft). The observed time interval delta(t) for her pulse is measured from Earth, which is at rest outside of the reference frame of the spacecraft. Then the relation between the two time intervals is given by:

delta(t) = gamma*delta(t_0);

and since gamma = 1/sqrt(1 - (v/c)^2) = 1/sqrt(1 - (0.100c/c)^2) = 1/sqrt(1 - 0.0100) = 1/sqrt(0.9900) = 1/0.9950 = 1.005, then:

delta(t) = 1.005*(1 second/pulse) = 1.005 seconds/pulse.

Student responses
Section 70856
(A) : 8 students
(B) : 2 students
(C) : 1 student
(D) : 0 students

Success level: 72%
Discrimination index (Aubrecht & Aubrecht, 1983): -0.33

20101218

Physics quiz question: CERN protons

Physics 205B Quiz 7, Fall Semester 2010
Cuesta College, San Luis Obispo, CA

Cf. Giambattista/Richardson/Richardson, Physics, 2/e, Problem 26.7.

The CERN Large Hadron Collider in Switzerland accelerates protons up to a speed corresponding to a Lorentz factor gamma of 3.000e3, as measured from a stationary reference frame (http://faculty.tamu-commerce.edu/cbertulani/cab/papers/7420.pdf). What is the speed of each proton?
(A) 0.9996667c.
(B) 0.9998333c.
(C) 0.9999998889c.
(D) 0.9999999444c.

Correct answer: (D)

The Lorentz factor gamma, in terms of the speed v is given by:

gamma = sqrt(1/(1 - (v/c)^2));

which can be algebraically manipulated to express v in terms of gamma:

gamma^2 = 1/(1 - (v/c)^2);

1 - (v/c)^2 = 1/(gamma^2);

(v/c)^2 = 1 - 1/(gamma^2);

v = c*sqrt(1 - 1/(gamma^2));

such that with gamma = 3.000e3;

v = c*sqrt(1 - 1/(3.000e3)^2) = c*sqrt(1 - 0.0000001111) = c*sqrt(0.9999998889) = 0.9999999444*c.

Response (A) is 1-(1/gamma); response (B) is sqrt(1-(1/gamma)); response (C) is 1-(1/gamma^2).

Student responses
Section 70856
(A) : 1 student
(B) : 1 student
(C) : 3 students
(D) : 6 students

Success level: 54%
Discrimination index (Aubrecht & Aubrecht, 1983): 0.67

20101217

Physics quiz question: radioactive decay age

Physics 205B Quiz 7, Fall Semester 2010
Cuesta College, San Luis Obispo, CA

Consider two samples with differing amounts of radioactive elements, embedded gaseous daughter elements, and inert material (which is not involved in the decay process). Which sample is older, as determined by radioactive dating?
(A) Sample A.
(B) Sample B.
(C) (There is a tie.)
(D) (Cannot be determined, as they have different amounts of inert material.)

Correct answer: (A)

The solidification age of a sample (how long ago has it been since it was last molten) is determined by the ratio of decay products to its unstable isotopes. A larger ratio of decay products to unstable isotopes corresponds to a sample with a very old solidification age.

Section 70856
(A) : 9 students
(B) : 2 students
(C) : 0 students
(D) : 0 students

"Success level": 81%
Discrimination index (Aubrecht & Aubrecht, 1983): 0.67

Related post:
  • Astronomy quiz question: radioactive decay age.
  • 20101216

    Astronomy quiz question: radioactive decay age

    Astronomy 210 Quiz 7, Fall Semester 2010
    Cuesta College, San Luis Obispo, CA

    Consider two samples with differing amounts of radioactive elements, embedded gaseous daughter elements, and inert material (which is not involved in the decay process). Which sample is older, as determined by radioactive dating?
    (A) Sample A.
    (B) Sample B.
    (C) (There is a tie.)
    (D) (Cannot be determined, as they have different amounts of inert material.)

    Correct answer: (A)

    The solidification age of a sample (how long ago has it been since it was last molten) is determined by the ratio of decay products to its unstable isotopes. A larger ratio of decay products to unstable isotopes corresponds to a sample with a very old solidification age.

    Section 70158
    (A) : 28 students
    (B) : 14 students
    (C) : 1 student
    (D) : 1 student

    "Success level": 67% (including partial credit for multiple-choice)
    Discrimination index (Aubrecht & Aubrecht, 1983): 0.67

    Section 70160
    (A) : 24 students
    (B) : 14 students
    (C) : 1 student
    (D) : 0 students

    "Success level": 52% (including partial credit for multiple-choice)
    Discrimination index (Aubrecht & Aubrecht, 1983): 0.17

    Related post:
  • Physics quiz question: radioactive decay age.
  • 20101215

    Astronomy quiz question: Venus' lack of plate tectonics

    Astronomy 210 Quiz 7, Fall Semester 2010
    Cuesta College, San Luis Obispo, CA

    Evidence that Venus does not have plate tectonics is:
    (A) runaway greenhouse effect.
    (B) no venusquakes detected by landers.
    (C) no subduction zones nor midocean rises.
    (D) no oceans.

    Correct answer: (C)

    Since the main features of plate tectonics are subduction zones and midocean rises, the lack of subduction zones and midocean rises on Venus is evidence of its lack of plate tectonics.

    Section 70158
    (A) : 6 students
    (B) : 5 students
    (C) : 29 students
    (D) : 4 students

    "Success level": 69% (including partial credit for multiple-choice)
    Discrimination index (Aubrecht & Aubrecht, 1983): 0.67

    20101214

    Astronomy quiz question: Mercury's lobate scarps

    Astronomy 210 Quiz 7, Fall Semester 2010
    Cuesta College, San Luis Obispo, CA

    __________ caused the long curving ridges on the surface of Mercury.
    (A) Lava flooding in lowland basins.
    (B) Compression and shrinking of the crust.
    (C) Convection currents underneath the crust.
    (D) Vertical motion of magma under the crust.

    Correct answer: (B)

    Mercury's rupes, or lobate scarps, were formed as its relatively thin crust wrinkled and shrank as its massive underlying core cooled and contracted.

    Section 70158
    (A) : 2 students
    (B) : 25 students
    (C) : 11 students
    (D) : 5 students

    "Success level": 60% (including partial credit for multiple-choice)
    Discrimination index (Aubrecht & Aubrecht, 1983): 0.75

    20101213

    Astronomy quiz question: Jupiter's liquid metallic hydrogen

    Astronomy 210 Quiz 7, Fall Semester 2010
    Cuesta College, San Luis Obispo, CA

    Jupiter's __________ is evidence that it contains liquid metallic hydrogen.
    (A) strong magnetic field.
    (B) cloud bands parallel to the equator.
    (C) flattened shape.
    (D) infrared radiation.

    Correct answer: (A)

    The circulation of Jupiter's liquid metallic hydrogen is the dynamo creating its strong magnetic field.

    Section 70158
    (A) : 17 students
    (B) : 15 students
    (C) : 1 student
    (D) : 11 students

    "Success level": 45% (including partial credit for multiple-choice)
    Discrimination index (Aubrecht & Aubrecht, 1983): 0.17

    20101212

    Astronomy quiz question: IAU classification scheme (2)

    Astronomy 210 Quiz 7, Fall Semester 2010
    Cuesta College, San Luis Obispo, CA

    Listed below are the minimal qualifications established by the International Astronomical Union for a planet:

    I. Orbits the sun.
    II. Shape "rounded-out" by gravity.
    III. Cleared/dominates orbit around sun.

    Of the following choices, which solar system object(s) meets only qualifications I and II?
    (A) Earth's moon.
    (B) Ceres, a dwarf planet.
    (C) Ida, an asteroid.
    (D) Mercury.
    (E) (More than one of the above choices.)
    (F) (None of the above choices.)

    Correct answer: (B)

    Ceres directly orbits the sun (it is not a satellite of a planet), is round in shape, but does not dominate its orbit in the asteroid belt around the sun.

    Section 70158
    (A) : 1 student
    (B) : 28 students
    (C) : 4 students
    (D) : 3 students
    (E) : 4 students
    (F) : 2 students
    (No response: 1 student)

    "Success level": 67% (including partial credit for multiple-choice)
    Discrimination index (Aubrecht & Aubrecht, 1983): 0.58

    20101211

    Astronomy quiz question: IAU classification scheme (1)

    Astronomy 210 Quiz 7, Fall Semester 2010
    Cuesta College, San Luis Obispo, CA

    Listed below are the minimal qualifications established by the International Astronomical Union for a planet:

    I. Orbits the sun.
    II. Shape "rounded-out" by gravity.
    III. Cleared/dominates orbit around sun.

    Of the following choices, which solar system object(s) meets only qualification II?
    (A) Earth's moon.
    (B) Ceres, a dwarf planet.
    (C) Ida, an asteroid.
    (D) Mercury.
    (E) (More than one of the above choices.)
    (F) (None of the above choices.)

    Correct answer: (A)

    Earth's moon is round in shape, but does not directly orbit the sun (it orbits Earth, which itself orbits the sun); and also Earth's moon does not dominate its orbit around the sun.

    Section 70160
    (A) : 25 students
    (B) : 4 students
    (C) : 5 students
    (D) : 0 students
    (E) : 5 students
    (F) : 0 students

    "Success level": 67% (including partial credit for multiple-choice)
    Discrimination index (Aubrecht & Aubrecht, 1983): 0.64

    20101210

    Physics quiz question: percent decrease in radioactivity

    Physics 205B Quiz 7, Fall Semester 2010
    Cuesta College, San Luis Obispo, CA

    Cf. Giambattista/Richardson/Richardson, Physics, 2/e, Problem 29.21.

    Americium-241 is used in smoke detectors, and decays via alpha decay with a half-life of 432 years. What is the percent decrease in activity for a sample of  in ten years?
    (A) 0.23%.
    (B) 0.33%.
    (C) 1.6%.
    (D) 2.3%.

    Correct answer: (C)

    The activity of a sample is given by:

    R = R_0*(1/2)^(t/T),

    where T is the half-life. Solving for the activity at t = 10 years, assuming that R_0 will be normalized to 1:

    (R/R_0) = (1/2)^(t/T) = (1/2)^(10 years/432 years) = 0.9840,

    So the percent decrease in 10 years will be 1 - 0.984 = 0.016, or 1.6%.

    Response (A) is 1/T; response (B) is the time constant tau = 1/(T*ln(2)); response (D) is 1 - exp^(-10/432), presumably confusing T with tau in the exponential decay formula.

    Student responses
    Section 70856
    (A) : 1 student
    (B) : 1 student
    (C) : 6 students
    (D) : 3 students

    Success level: 54%
    Discrimination index (Aubrecht & Aubrecht, 1983): 0.67

    20101209

    Astronomy quiz question: Venus versus Earth's moon

    Astronomy 210 Quiz 7, Fall Semester 2010
    Cuesta College, San Luis Obispo, CA

    The small number of impact craters on Venus, compared to Earth's moon, is evidence of Venus':
    (A) past oceans.
    (B) lack of shield volcanoes.
    (C) lack of tidal heating.
    (D) younger surface.

    Correct answer: (D)

    The surfaces of all terrestrial planets (and Earth's moon) accumulated impact craters during the heavy bombardment phase of planetary formation. Geological activity is responsible for removing these impact craters (filling in with lava, folding down into the mantle from tectonic plate motion), such that a lack of impact craters corresponds to a greater amount of geological activity, and a newer (more recently solidified) surface.

    Section 70160
    (A) : 14 students
    (B) : 3 students
    (C) : 1 student
    (D) : 21 students

    "Success level": 58% (including partial credit for multiple-choice)
    Discrimination index (Aubrecht & Aubrecht, 1983): 0.39

    20101208

    Found physics: joule thief

    101114-1200240
    http://www.flickr.com/photos/waiferx/5193443136/
    Originally uploaded by Waifer X

    Joule thief (en.wikipedia.org/wiki/Joule_thief), built with Radio Shack parts and a mint tin, circuit diagram based on Make magazine's how-to tutorial (http://makezine.com/2007/11/02/make-a-joule-thief-weeken-1/).

    20101207

    Astronomy current events question: extra-galactic planet

    Astronomy 210L, Fall Semester 2010
    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, "Planet from Another Galaxy," November 18, 2010
    http://www.skyandtelescope.com/news/108739724.html
    Astronomers were able to determine that the star HIP 13044 and its orbiting planet may have come from beyond the Milky Way galaxy by analyzing their:
    (A) trajectory.
    (B) metallicity.
    (C) gravitational wobbles.
    (D) orbital motion.
    (E) absorption and emission spectra.

    Correct answer: (A)

    Student responses
    Sections 70178, 70186, 70200
    (A) : 5 students
    (B) : 10 students
    (C) : 8 students
    (D) : 4 students
    (E) : 3 students

    20101206

    Astronomy current events question: Rhea's thin atmosphere

    Astronomy 210L, Fall Semester 2010
    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!)
    Jia-Rui C. Cook, "Thin Air--Cassini Finds Ethereal Atmosphere at Rhea," November 26, 2010
    http://www.nasa.gov/mission_pages/cassini/whycassini/cassini20101126.html
    The NASA Cassini spacecraft has detected a thin atmosphere around Saturn's moon Rhea, containing oxygen that may be released from:
    (A) pockets containing pristine solar nebula gas.
    (B) high energy particles bombarding its icy surface.
    (C) subsurface organisms capable of photosynthesis.
    (D) chemical processes that may eventually evolve into life.
    (E) radioactive decay processes.

    Correct answer: (B)

    Student responses
    Sections 70178, 70186, 70200
    (A) : 4 students
    (B) : 22 students
    (C) : 7 students
    (D) : 14 students
    (E) : 8 students

    20101205

    Astronomy current events question: Jupiter's south equatorial belt

    Astronomy 210L, Fall Semester 2010
    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!)
    Emily Lakdawalla, "Jupiter's Outbreak is Spreading," November 22, 2010
    http://planetary.org/blog/article/00002784/
    Amateur astronomers have been observing recent rapid changes in Jupiter's:
    (A) two moons that may soon collide.
    (B) polar ice caps.
    (C) lightning storms.
    (D) magnetic field.
    (E) weather patterns.

    Correct answer: (E)

    Student responses
    Sections 70178, 70186, 70200
    (A) : 0 students
    (B) : 1 student
    (C) : 0 students
    (D) : 5 students
    (E) : 20 students

    20101204

    Online reading assignment question: Venus, Mars tags

    Astronomy 210, fall semester 2010
    Cuesta College, San Luis Obispo, CA

    101201-venuswordle
    http://www.flickr.com/photos/waiferx/5224882904/
    Originally uploaded by Waifer X

    Wordle.net tag cloud for "Venus" generated by responses from Astronomy 210 students at Cuesta College, San Luis Obispo, CA (http://www.wordle.net/show/wrdl/2817770/Untitled).


    101201-marswordle
    http://www.flickr.com/photos/waiferx/5224882826/
    Originally uploaded by Waifer X

    Wordle.net tag cloud for "Mars" generated by responses from Astronomy 210 students at Cuesta College, San Luis Obispo, CA (http://www.wordle.net/show/wrdl/2817749/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.

    (The following question was asked prior to lectures on the terrestrial planets.)

    Write down five words that describe or are associated with "Venus." Keep word phrases together with no spaces between them (e.g., "veryhot"). (Graded for completion.)

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

    Student responses
    Sections 70158, 70160
    large hot terrestrial dense women
    razors, planet, veryhot, goddess, veryhot
    circlularorbit rocky noweather beauty craters
    goddess, female, rocky, volcanoes, planet
    goddess razors planet sisterplanet dry
    cloudy, dry desert, craters, volcanoes, hot
    goddess greenhouse superhot
    plant, terrestrial, active, big, guys
    denseatmosphere, sisterplanet, 224.7earthdays, brightinsky, visiblewithouttelescope
    womenarefrom menarefromMars
    razors, hot, faraway, rocky, big
    greenhouse, hot, atmosphere, goddess
    hot, acid, rain, melt, atmosphere
    hot, terrestrial, sulfuricacidclouds, denseatmosphere, Romangoddess
    yellow, medium, secondplanet
    blue cool outerspace whoknows
    redspot, giant, gasgiant, storms, hurricanes
    women yellow goddess love
    greenhouse, secondplanet, denseatmosphere, meltslead, carbondioxide
    veryhot, faraway,
    girls planet goddess flytrap space
    coronae, greenhouse, cloudy, meltslead, closertosun
    acidrain, secondplanet, CO2, nomoons, morningstar
    planet hot Serena tennis orbit
    Earthsize, acidrain, volcanoes, fewcraters, platetectonics
    smaller, morningstar, close, rocky, veryhot
    hot, humid, acid, greenhouse, pressure
    secondplanet, Earthsize, volcanoes, lavaflows, closertosun
    razors, girls, eveningstar, solar system, beauty
    big, toomanybeans, gassy
    cloudy, volcanoes, hot, Earthsize, goddess
    Earthsize, bright, terrestrial, inferiorplanet, goddess
    planet, terrestrial, inferiorplanet, sisterplanet, Earthlike
    cloudy, bright, volcanoes, lavaflows, craters
    dark, cold, nolife, nowater, rocky
    planet, hot, solar, system, world
    planet razors space pretty awesome
    bright veryhot morningstar eveningstar sulfur
    secondplanet, brightinsky, denseatmosphere, desert, goddess
    feminine planet hot notEarth
    cloudy, drydesert, volcanoes, craters, basaltic lowlands
    deadlygases sisterplanet hot uninhabitable bright
    secondplanet atmosphere hot cloudy uninhabitable
    closertosun hot fire doom die sad
    goddess mythology planet car heavens
    Venus veryhot terrestrial
    hot superhot ohmysohot
    veryhot, goddess love, womenarefrom, terrestrial, kindabig
    hot, greenish, gasatmosphere, sisterplanet, Earthsize
    razors,
    hot, goddess love, terrestrial, AphroditeTerra, volcanoes
    Earthsize Libra veryhot
    big warm volcanoes red craters
    Earthsize unbreathableair inhabitable cloudy craters
    hot dead inactive goddess
    goddess, love, beauty, borninaseashell, screwedParisover, womenarefrom
    veryhot cloudy hot desert CO2 coronae
    women planet closertosun inhabitable
    Remus, Demus, fetus, Metus, Peanuts
    razors planet rocky hot
    girls razors goddess love
    secondplanet sister bright love beauty
    hot innerorbit SailorMoon
    razors, tennis, planet, shaving, hot
    Write down five words that describe or are associated with "Mars." Keep word phrases together with no spaces between them (e.g., "redplanet"). (Graded for completion.)

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

    Student responses
    Sections 70158, 70160
    terrestrial small men chocolate red
    red, candybar, martians, rovers, MissiontoMars
    small red water? Phobos Deimos craters
    god, martians, red, male, war
    red god planet aliens polaricecaps
    thinatmosphere, littlewater, craters, volcanoes, deserts
    red lamerversionofEarth
    women, planet, big, active, terrestrial
    fourthplanet, thinatmosphere, craters, volcanoes, valleys
    men aliens red martians candybar
    aliens, candybar, far, cold, red
    red, god, rovers, ice, fourthplanet
    cold, red, god, Phobos Deimos, dirt
    ironoxide, terrestrial, thinatmosphere, Phobos Deimos, rovers
    candybar, fourthplanet
    red hot solarsystem cool
    dust, ice, terrestrial, mudvolcanoes, life?
    men red god
    thinatmosphere, volcanoes, red, water?, polaricecaps
    red, volcanoes, faraway, water?
    pyscho red valleys deserts craters
    cold small, permafrost, Phobos Deimos, polaricecaps, volcanoes
    red, butterscotchcolor, VallesMarineris, thinatmosphere, Phobos Deimos
    candybar chocolate nexthome?
    polaricecaps, thinatmosphere, red, stormy, nexthome?
    red, fourthplanet, god, volcanoes, deserts
    cool, arid, craters, red, small
    red, fourthplanet, small volcanoes, outflowchannels
    boys, candybar, solarsystem, fourthplanet, red
    martians, face, red
    polaricecaps, cold, candybar, waterflow, Phobos Deimos
    ironoxide, god, red, terrestrial, OlympusMons
    red, BorealisBasin, thinatmosphere, ironoxide, terrestrial
    weather, complexgeology, craters, volcanoes, water
    life?, dark, cold, rocky, red
    Mars, Venus, Earth, Saturn, Uranus
    water? planet life? space cool
    red canyon dust polaricecaps faraway
    MarvintheMartian, ice water?, fourthplanet, volcanoes, candybar
    hot planet dry nolife
    thinatmosphere, polaricecaps, OlympusMons, craters, Phobos Deimos
    face craters OlympusMons Phobos Deimos
    fourthplanet red Phobos Deimos war
    aliens cold scarymovies martians
    god war red planet anger
    red
    red aliens close candybar water?
    red, god war, menarefrom, volcanoes, deserts
    volcanoes, polaricecaps, red dust, similargravityanddaylengthtoEarth
    candybar, movies, big, red, rovers
    red, cool, face, god, ironoxide
    red rovers martians craters ice
    small cool inactive orange yeah
    water? nonbreathableair thinatmosphere volcanoes longvalleys
    rusty dead war cold red
    menarefrom, red, stormy, cold, permafrost
    thinatmosphere permafrost volcanoes outflowchannels valleys
    war god red onemoon exoplanet habitable
    candybar, planet, rotation, revolution, solarsystem
    mountians red dust
    red thinatmoshpere craters
    fourthplanet red war martians planet
    red dust life?
    red, planet, life?, warm, stormy


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