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Re: [Phys-l] Centrifugal redux

It isn't the the "centrifugal force" that crushes you, but rather the
locally applied normal force. You die with or without the "centrifugal
force" if just the high normal force is applied, but without the normal
force and only the "centrifugal force" you survive.

And for those who think the students understand frame of reference try the
modified Atwood test. It is easily framed as a multiple choice question.
"Which way does a coat left on a car go as it falls when the car accelerates
to the right. Give the answer from the point of view of a person standing
still on the curb." You may be surprised.

John M. Clement
Houston, TX



Check out the comic strip http://xkcd.com/123/ for a slightly different
take on this issue.

Zeke Kossover



----- Original Message ----
From: Ken Fox <physicsfox23@gmail.com>
To: Forum for Physics Educators <phys-l@carnot.physics.buffalo.edu>
Sent: Wednesday, March 18, 2009 8:16:49 AM
Subject: Re: [Phys-l] Centrifugal redux

From Rick Tarara:
"........but of course in the accelerating frame you have to give up
Newton's laws (especially the third)
since there is no agent to which you can assign the centrifugal force."


Understanding frame of reference is essential and well within the
capability
of my high school students. We tend to stick with the inertial frame as
has
been suggested. But we live in many accelerated frames, cars and
airplanes
and amusement park rides.

As for agents of a force, how imaginary is gravity?

Let's hear it for the Principle of Equivalence and a possible extension
to
Centrifugal Fields. I notice such every time in the winter when I turn
left
and feel hot air come my way. High school students can easily grasp such
ideas.

Ken Fox
_______________________________________________
Forum for Physics Educators
Phys-l@carnot.physics.buffalo.edu
https://carnot.physics.buffalo.edu/mailman/listinfo/phys-l




_______________________________________________
Forum for Physics Educators
Phys-l@carnot.physics.buffalo.edu
https://carnot.physics.buffalo.edu/mailman/listinfo/phys-l