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[Phys-L] It's more engineering and less physics? was: Re: [Phys-l] HS physics McGyver demo and activity blog


On 2010, Jan 17, , at 14:21, John Denker <jsd@av8n.com> wrote:

Hi Folks --

I recently ran across an interesting blog.
http://teachingphysics.wordpress.com/
http://teachingphysics.wordpress.com/welcome-to-a-resource-for-physics-teachers/




Among the good points:
-- There is a commendable emphasis on critical
thinking, for instance the unit on the elusive
Pacific tree octopus.
-- There is a commendable emphasis on having the
students build stuff. Improvisational building,
as opposed to following a cookbook.

I have to wonder about the level of some of the
projects. The last time I built catapults out of
popsicle sticks, the builders were 9-year-old Cub
Scouts. My first thought was that I'd be embarrassed
to do it with HS seniors ... but on second thought
I guess it depends on the group. If they've never
built anything before, almost anything is better
than nothing. You can sometimes upgrade this sort
of activity, by calling for bigger structures, more
precision, et cetera. Also the activity is predicated
on having enough hot glue guns to go around, which is
not always the case ... and I'm not even sure it's
a good idea. By the time kids reach HS physics,
they should be using more appropriate adhesive
technology.

The blog contains some seriously misguided ideas
about "the scientific method".


Anyway ... you might want to take a look and decide
for yourself. It doesn't take long to skim the site.
It provides food for thought.


As JD’s post is four year old I skimmed and found this:
"...
This is not a new topic for me, it’s been a burr in my saddle for some time now. All of the introductory physics textbooks address significant figures in much the same way. The problem is – nobody in the “real world” (as if school isn’t real?) uses sig figs. At the same time, introductory physics isn’t the time to introduce complex error analysis models. …"

Also I didn’t find find the Sci. method.

However, the reason I post is my apprehension physics teaching projects are becoming engineering, e.g. egg drop, bridge building (here it’s polystyrene cement (I think.), and trebuchets. AND in JR college too! But as JD wrote, anything is better than none, but can’t teachers and students dream up physics projects? In my HS no projects. Mine were at home on vacation from prep school (800+ MHz oscillator using 6J6 and wavelength using my lecher wires; constructing amateur short wave 20W transmitter, etc.)

Further: one of Scott’s proposed activities:

I will project an archery target on the board.
Students will move back about 20 feet and shoot a round of Nerf darts at the target. They will be far enough back that most of them will shoot a 6, or 7 and not a 9 or 10, at least at first. Each student will take a turn.
We will plot the overall results. We should get something resembling a normal distribution curve, but I won’t tell them that.
I will ask the kids to average the data and come up with a value of x.x +/- y.y and start a discussion on whether or not that represents the data.
We will then put a ring or other object on an electronic scale and write the mass with the error in the same way.
After some discussion, I will bring up slides of normal, rectangular, triangular, and maybe exponential distribution curves. I want them to discuss the fit of the models to the data.
My goal is that they understand that error is probability.
About a week later we will drop rulers and calculate individual reaction times. This would be a good time to bring back the distribution graphs and perhaps even input our data into a statistical analysis program to find the best fit.
I think this will work and go over well. I’d love some feedback. It’s a first pass, what did I miss?

bc