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Re: PER - FREE BODY DIAGRAMS



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In her Phys-L post of 24 Jul 2003 14:18:08-0400 titled "PER - FREE
BODY DIAGRAMS," Mary Hing-Hickman wrote (slightly edited):

"Does anyone know of any Physics Education Research (PER) involving
free body diagrams? I am currently aware of the articles by James
Court (1993), the late Peter Whiteley (1995), and Kurt Fisher
(1999)." [The cryptic notation "Kurt Fisher (1999)" means that if one
scrolls down to "REFERENCES" s(he) will find the full reference at
"Fisher, K. 1999."]

In response:

1. Joe Bellina on 24 Jul 2003 21:46:57-0500 wrote: "Lillian
McDermott's group has done some. There is even a very nice software
package sold by the AAPT based on that work."

2. Aaron Titus on 24 Jul 2003 23:04:38-0400 wrote (slightly edited):
"An excellent piece of software is 'FreeBody' [by Graham Oberem of
Cal State - San Marcos]. . . 'FreeBody' is sold by Physics Academic
Software <http://webassign.net/pasnew/freebody/freebody.html>."

According to information at the above URL "[FreeBody] UTILIZES
ARTIFICIAL INTELLIGENCE (my CAPS) to teach students to construct
free-body diagrams. . . [and]. . . was developed in the Physics
Education Group at the University of Washington. It is based on sound
educational research and addresses misconceptions commonly shared by
students new to the study of mechanics." See also the discussion of
"Freebody" at
<http://physics.csusm.edu/physics/faculty/oberem/personal/oberem.html>.

But it may be awhile before "artificial intelligence" will even come
close to being as effective as an expert HUMAN Socratic Dialogist.
Here the dialogist emulates the HISTORICAL Socrates of Vlastos
(1991), NOT Plato's alter ego in the "Meno," as explained in footnote
#39 of the suppressed Hake (1998b). Unfortunately, Plato's alter ego
is naively assumed by Morse (1994), Swartz (2000), and Redish (2003)]
to be the real Socrates.

Unknown to most physics teachers and generally ignored by PER's
[e.g., Redish & Rigden (1997), McCray et al. (2003)] Socratic
Dialogue Inducing (SDI) Labs [Hake (1992, 2002)] and particularly Lab
#1 "Newton's First and Third Laws" (Hake 1998a) emphasize, among
other things, the drawing of Free Body Diagrams (FBD's). As indicated
in the Teacher's Guide for Lab #1 (Hake 1995):

HHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH
SDI Labs stress:

1. The construction of SINGLE "force-motion-vector diagrams [FMVD],"
rather than SEPARATE force and motion diagrams as advised by Heller
and Reif (1984) [but Reif (1994, 1995) later advised drawing a SINGLE
"system diagrams" similar to a FMVD's].

2. Embedding of the standard FBD in context so that motion
constraints and TOUCHING bodies can more easily be kept in mind by
beginners.

Our experience indicates that both "1" and "2" facilitate the
application of the extremely effective "Heller-Reif" (HR) strategy
[Heller & Reif (1984); Hake (1992)] for delineating and checking
forces. The embedding of the FBD is facilitated by coloring (yellow)
the body to which Newton's First or Second Law is applied.
HHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH

Thus FMVD's show, in addition to the BODY itself:

a. all vector forces F acting ON the body ALWAYS labeled as F(on A by
B), where F is due to the interaction (either contact or action at a
distance) on body A by body B.

b. the velocity v and acceleration a vectors for the BODY, if such exist,

c. objects that TOUCH the BODY.

In non-ASCII, the vector nature or F, v, and a would be shown by
arrows above the letters, and the quantities in parentheses would be
shown as subscripts.

Labeling forces as F(on A by B) allows relatively straightforward
treatment of Newton's Third Law (N3) as simply

F(on A by B) = - F(on B by A). . . . . . (N3)

I call this the fail-safe "AB switch" method for finding N3 pairs.

An important feature of FMVD's is the COLOR CODING of vectors for
force, velocity, and acceleration, as well as the color coding of the
center of Newton's attention "The BODY."

FMVD's are also useful in the form of FMVA's [Force Motion Vector
Animations - as can be provided by e.g., Interactive Physics
<http://www.interactivephysics.com>], provided FMVA's are only used
AFTER students work out the FMVD's via interactive engagement with
peers and Socratic Dialogists- or, if the later are unavailable, with
"artificial intelligence."

BTW, a quick review of recent copies of "The Physics Teacher" turned
up a few more articles relevant to FBD's: Court (1999a,b); Lane
(1993a,b); Mathot (1993), Newburgh (1994); Sperry (1994).


Richard Hake, Emeritus Professor of Physics, Indiana University
24245 Hatteras Street, Woodland Hills, CA 91367
<rrhake@earthlink.net>
<http://www.physics.indiana.edu/~hake>
<http://www.physics.indiana.edu/~sdi>


REFERENCES
Court, J.E. 1993. "Free-Body Diagrams," Phys. Teach. 31(2): 104-108.

Court, J.E. 1999a. "Free-Body Diagrams Revisited - I," Phys. Teach.
37(7): 427-433.

Court, J.E. 1999b. "Free-Body Diagrams Revisited - II," Phys. Teach.
37(8): 490-495.

Fisher, K. 1999. "Exercises in drawing and utilizing free-body
diagrams," Phys Teach. 37(7): 434-435: "A very useful aid to sorting
out the relevant forces in a mechanics problem is the ON/B¥ table,
which I have recently begun to require as part of solution to tests.
The idea for this table came from perusing one of the "Socratic
Dialogue Inducing (SDI) Labs. . ."
Hake, R.R. 1992. "Socratic pedagogy in the introductory physics lab."
Phys. Teach. 30: 546-552; updated version (4/27/98) online as ref. 23
at <http://www.physics.indiana.edu/~hake>.

Hake, R.R. 1995. "Teacher's Guide: SDI Lab #1, Newton's First and
Third Laws." Soon to be on the web at the Harvard Galileo site
<http://galileo.harvard.edu/> / "Socratic Dialogue Inducing Labs"
/"Resources for SDI" / "Teacher's Guides", where "/" means "click
on." A less scenic direct route is via
<http://galileo.harvard.edu/galileo/hom/sdi/docs.html>. Teacher's
Guides for SDI Lab #0.2 "Introduction to Kinematics," and SDI Lab #3
"Circular Motion and Frictional Forces," are already at that site.

Hake, R.R. 1998a. SDI Lab #1, "Newton's First and Third Laws"; online
at <http://www.physics.indiana.edu/~sdi>.

Hake, R.R. 1998b. SDI Lab #3, "Circular Motion and Frictional
Forces"; online at <http://www.physics.indiana.edu/~sdi>. A Teacher's
Guide is at the Harvard Galileo site <http://galileo.harvard.edu/> /
"Socratic Dialogue Inducing Labs" /"Resources for SDI" / "Teacher's
Guides", where "/" means "click on." A less scenic direct route is via
<http://galileo.harvard.edu/galileo/hom/sdi/docs.html>.

Hake, R.R. 1998c. "Interactive-engagement vs traditional methods: A
six-thousand-student survey of mechanics test data for introductory
physics courses," Am. J. Phys. 66, 64-74 (1998); online as ref. 24 at
<http://www.physics.indiana.edu/~hake>.

Hake, R.R. 1998d. "Interactive-engagement methods in introductory
mechanics courses," online as ref. 25 at
<http://www.physics.indiana.edu/~hake>. SUBMITTED on 6/19/98 to the
"Physics Education Research Supplement to AJP"(PERS). In this sadly
unpublished (Physics Education Research has NO archival journal!)
crucial companion paper to Hake (1998c): average pre/post test
scores, standard deviations, instructional methods, materials used,
institutions, and instructors for each of the survey courses of Hake
(1998a) are tabulated and referenced. In addition the paper
includes: (a) case histories for the seven IE courses of Hake (1998a)
whose effectiveness as gauged by pre-to-post test gains was close to
those of T courses, (b) advice for implementing IE methods, and (c)
suggestions for further research.

Hake, R.R. 2002. "Socratic Dialogue Inducing Laboratory Workshop,"
Proceedings of the UNESCO-ASPEN Workshop on Active Learning in
Physics, Univ. of Peradeniya, Sri Lanka, 2-4 Dec. 2002; also online
as ref. 28 at
<http://www.physics.indiana.edu/~hake/>.

Heller, J.I. & F. Reif. 1984. "Prescribing Effective Human
Problem-Solving Processes: Problem Description in Physics," Cognition
and Instruction 1: 177.

Lane, B. 1993a. "Why Can't Physicists Draw FBD's?" Phys. Teach. 31(4): 216-217.

Lane, B. 1993b. "Response to Mathot," Letter to the editor, Phys.
Teach. 31 (7): 390.

Mathot, L.G. 1993. "Free Body Diagrams," Letter to the editor
regarding Lane (1993a). Phys. Teach. 31 (7): 390.

McCray, R.A., R.L. DeHaan, J.A. Schuck, eds. 2003. "Improving
Undergraduate Instruction in Science, Technology, Engineering, and
Mathematics: Report of a Workshop" Committee on Undergraduate STEM
Instruction," National Research Council, National Academy Press;
online at <http://www.nap.edu/catalog/10711.html>. Physicists
attending the workshop were Paula Herron, Priscilla Laws, John
Lehman, Ramon Lopez, Richard McCray, Lillian McDermott, Carl Wieman,
and Jack Wilson.

Morse, R.A. 1994. "The Classic Method of Mrs. Socrates," Phys. Teach.
32: 276-277.

Newburgh, R. 1994. "Force Diagrams: How and Why?" Phys. Teach. 32 (6): 352.

Redish, E.F. 2003 "Teaching Physics With the Physics Suite." John Wiley.

Redish, E.F. & J.S. Rigden, eds. 1997. "The Changing Role of Physics
Departments in Modern Universities: Proceedings of the ICUPE." AIP.

Reif, F. 1994. "Understanding Basic Mechanics" (Text and Workbook). Wiley.

Reif, F. 1995. "Millikan Lecture 1994: Understanding and teaching
important scientific thought processes," Am. J. Phys. 63(1): 17-32.

Sperry, W. 1994. "Placing the Forces on Free-Body Diagrams," Phys.
Teach. 32 (6): 353.

Swartz, C. 2000. "Buzzwords and Newspeak," Editorial, Phys. Teach. 38(3): 134.

Vlastos, G. 1991. "Socrates, Ironist and Moral Philosopher" (Cornell
Univ. Press, 1991), esp. Chap. 2, "Socrates contra Socrates in Plato."

Whiteley, P. 1994. "What 'Holds Up' the Moon?" Phys Teach. 32(6):
348-349. For the SDI counterpart see Hake (1998b), Section IIC "The
Moon."

Whiteley, P. 1995. "Using Free Body Diagrams as a Diagnostic
Instrument," submitted to Phys. Teach. See also Whiteley (1994).