Hello Ethan,
Please help me fill in the blanks
1. a body at rest tends to --------- at rest
2. a body in motion tends to -------- in motion
3. For every action there is an ---------and------------ re-action
Thank you, E.B., Weston, Ontario, Canada
Hello E.B.:
Aristotle's work in Physics has never really gone away. He taught us that a
moving object's motion is maintained by a "mover". Galileo proved
Aristotle wrong when he taught us that it takes a force to change an object's motion and
with the absence of such an acceleration-causing action force, the moving object has no choice but to continue on with
its motion unchanged. No "mover" required.
The problem is that scientists smiled at Galileo, patted him on the
back and went right on believing in Aristotle's "mover" having renamed it inertia. Newton,
with his overly broad description of matter's inertia property, wrote that an object's
motion is
"maintained by its inertia only" which is just the same as Aristotle telling us that an object's motion is maintained by a
"mover". So much for our learning anything from Galileo.
Accordingly, to answer your three questions:
(1) A body at rest (rest-motion) doesn't "tend" to do anything. It
has no choice but to wait in its current state of uniform motion (rest-motion) for the next acceleration-causing action force to come
along. The wait can be for a lifetime. Meanwhile the object's current state of
rest-motion will continue
on due not to the presence of Aristotle's "mover" or Newton's version
of inertia but to the
simple absence of an
acceleration/Action force. (See Article I Defining Inertia.)
(2) Given the equality of rest and uniform motion (rest-motion), see (1).
(3). Every action force is equally opposed by a reaction force,
another action force or combination thereof. This simplification of the
Universal Law of Mutual Forces is more accurate than the first half of Newton's LAW
III. (See Article III, The Equality of Opposing
Forces.)
If you are so inclined, I have a question I would like you to
answer.
[1]. Given that every force is always opposed by an equal force, then how is
a "net" or "overall" or "unbalanced" or "unopposed" force possible? If you know how, please describe an event that will reveal to me
the reality of such a Newton's-LAW-III-violating force.
Thank you for visiting the Universal Physics Journal.
Ethan Skyler
December 30, 2001
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