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Re: [Phys-l] Simulations and Computer Homework Problems for Freshman and Sophomores



Hi all;

I have been using simulations for some time (6-8 years) when I teach either the algebra or calculus based intro physics. I use mostly Open Source physics from Wolfgang Christian's group (scroll down on http://homepages.ius.edu/kforinas/Forinash.html to see some examples). My experience is that for things like waves and electromagnetic fields it seems to help. Most students can visualize mechanical situations like car crashes and pendulums but have no intuitive feeling for the behavior of fields or electricity. This would be my only criticism of the earlier posts on Interactive Physics. IP has many nice simulations of mechanics and even electric circuits but does not seem to have examples of fields. The other limitation of IP is making interactive simulations (not just visualizations) available on the web on multiple platforms.

Simulations have to be interactive. They can't be just visualizations. Students have to be able to change the parameters, to experiment. One purpose of a simulation is to provide a limited environment where students can modify a few things without having to delve deeply into programing issues, or create the entire physical system from scratch. Given a simulation which provides a limited situation allows the student to experiment without starting from a blank slate, from scratch.

Unfortunately we do not have a lot of hard physics education research that simulations do any good. There are a few papers (which I will look for later) but someone should probably do a lot more education research on this issue. There is at least one paper that shows that students using Phet simulations (http://phet.colorado.edu/) for circuits actually do BETTER on post testing than if they only work with a real circuit.

I also assign a spreadsheet modeling exercise that includes friction for projectile motion. This makes projectile motion more realistic (moving beyond the textbook ideal case) but also introduces the power of computer modeling since the solutions cannot be written in closed form. The spreadsheet I use includes the possibility of non-physical results (projectiles reversing direction because of friction) to emphasize the point that simulations are only as good as you make them; they can and will lie to you if you don't understand what is going on. This is a point that surprises many of the computer science majors in my class.

Recently I have begun to see a shift towards eBooks (I am with Indiana University and they have just made an agreement with several large publishers to provide eTexts to students at a discount). I think this shift will happen very rapidly. Unfortunately most eBooks are just pdfs of existing texts. But there is the potential to embed simulations (and video, etc.) in a text. A text that you have to interact with in order to get through reading it. I have a prototype eBook on waves at http://homepages.ius.edu/kforinas/W/Waves.html and welcome any comments.

kyle





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Message: 1
Date: Sat, 10 Dec 2011 10:46:33 -0500
From: "Donald Polvani" <dgpolvani@verizon.net<mailto:dgpolvani@verizon.net>>
Subject: [Phys-l] Simulations and Computer Homework Problems for
Freshman and Sophomores
To: "'Forum for Physics Educators'"
<phys-l@carnot.physics.buffalo.edu<mailto:phys-l@carnot.physics.buffalo.edu>>
Message-ID: <000001ccb752$e4c37dc0$ae4a7940$@net>
Content-Type: text/plain; charset="us-ascii"

I am an adjunct physics instructor teaching at a community college. I have
been trying to get the full time faculty to add computer simulations to
their lab courses and computer programming to their homework assignments.
The lab simulations need not replace the physical lab but could supplement
the existing lab by pre (or post) showing the students how typical results
"should" turn out. Another use of the simulation would be to indicate the
effect of factors which would be impractical to demonstrate in the physical
lab (e.g. air resistance, fall off of gravity with distance from the earth,
averaging of random errors as the number of measurements becomes large,
etc.). An example of a computer homework problem would be the
"Skateboarders rock at physics" problem discussed in the latest Science
News, 12/3/11, p10. Here students are given the choice of skateboarding
down either a shorter incline angling down modestly but without changing
slope (Case a) compared with a relatively longer incline angling steeply
downward in two sections (Case b). The article claims that Case b is the
correct choice and is the intuitive choice of students who skateboard. This
problem can be solved with basic freshman/sophomore physics (algebra based).
When I did this and implemented the solution in a simple Excel program, I
found that for certain ranges of parameters (relative steepness of the
slopes and relative lengths and heights of the inclined sections) Case a
would actually be the better choice while for other parameter choices Case b
was, in fact, better. Such a problem is solvable with elementary physics
equations but is onerous to compute for the wide range of parameters needed
to completely span the solutions. Seeing how the solutions vary with
parameter choices and then trying to physically understand the behavior
seems to me highly worthwhile and not feasible with a few hand calculations.
Assigning a few such problems, over the semester, as homework (or even a
full lab session ) seems worthwhile to me.



While the full time instructors acknowledge that such computer
simulations/homework may be useful, they maintain that such work
(particularly, the lab simulations) belongs in junior/senior year level
courses and the freshman/sophomore courses we exclusively teach (as a
community college) should only contain real physical measurements. I feel
that, at least, a small portion of our labs and homework should involve
computer simulations and programming. I've seen at what a young
(pre-school) age my grandchildren are becoming computer literate. I think
our modern freshmen and sophomores are easily up to using (and, perhaps,
even writing) lab simulations and certainly writing simple Excel programs to
solve problems like the skateboarding problem.



I feel our graduating sophomores may be behind their peers at other
institutions who have already started down the computer simulations/homework
path, but I don't have any data on what other institutions (either 2 year or
4 year ) are doing.



I'd appreciate your inputs on your experiences on either using such
simulations/homework in freshman/sophomore courses or why you have not done
so.



Don



Dr. Donald G. Polvani

Anne Arundel Community College

Arnold, MD 21012



---------------------------------------------------------
'Before you open your mouth, just remember,
the empty wagon rattles the loudest.'
-- my dad

kyle forinash 812-941-2039
kforinas@ius.edu<mailto:kforinas@ius.edu>
http://homepages.ius.edu/kforinas/Ebook/Site/Blog/Blog.html