| Topic: |
Science > Physics |
| User: |
"eddie jw" |
| Date: |
25 Oct 2005 10:27:01 AM |
| Object: |
Passing Zero |
How is it possible for something to pass zero and still know where it is
heading? When something is zero it has no information on itself.
.
|
|
| User: "Al Zenner" |
|
| Title: Re: Passing Zero |
25 Oct 2005 04:34:29 PM |
|
|
"eddie jw" <jw@telkomsa.net> wrote in
news:djlmat$iim$1@ctb-nnrp2.saix.net:
How is it possible for something to pass zero and still know where it is
heading? When something is zero it has no information on itself.
http://wordnet.princeton.edu/perl/webwn?s=zero
Which definition would you like to use? In order to undertake a
discussion one must first make certain that everyone is on the
same page.
Here's something to ponder. "When something is zero" is describing
an impossible situation so that anything you might think a result
is invalid because the underlying premise is invalid.
Any second trollish question in this thread is destined to be ignored.
.
|
|
|
|
| User: "Sam Wormley" |
|
| Title: Re: Passing Zero |
25 Oct 2005 11:36:21 AM |
|
|
eddie jw wrote:
How is it possible for something to pass zero and still know where it is
heading? When something is zero it has no information on itself.
Consider a parachutist decenting from 1000 feet above mean sea
level over the Mojava Dessert. The parachutist carries an altimeter
which is reading:
1000, 900, ..., 200, 100, 0, -100, -200, -282
.
|
|
|
|
| User: "PD" |
|
| Title: Re: Passing Zero |
25 Oct 2005 11:50:05 AM |
|
|
eddie jw wrote:
How is it possible for something to pass zero and still know where it is
heading? When something is zero it has no information on itself.
Actually, there is more information available than just position. The
*change* in position is also available, the *change in the change* of
the position is also available, and so on.
A classic example of this is tossing a ball in the air. The ball
decelerates on the way up with an acceleration equal to 9.8 m/s/s. The
ball accelerates on the way down with an acceleration equal to 9.8
m/s/s. What is its acceleration at the very top of the flight where,
for an instant, its velocity is zero? It is *still* accelerating at 9.8
m/s/s. If it were not, then its velocity would not change at the top
and it would perpetually have a velocity of zero, just hanging in
space.
PD
.
|
|
|
|
|
Related Articles |
|
|
