An object dropped instantaneously from rest is modeled well by a
discontinuous acceleration function, its zero then instantaneously goes to
g. Namely, the example that has been discussed!
Note, I'm not saying the acceleration is discontinuous, I'm saying its
motion is modeled well by such an acceleration function. The model does not
have to correspond to reality *exactly*; it only has to be a reasonable
approximation for the purposes at hand.
Joel
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From: Alex. F. Burr
To: QuistO; RAUBERJ; phys-l
Subject: RE: Models, etc.
Date: Thursday, October 30, 1997 1:01PM
Can anybody think of a process in nature (excepting quantum mechanical
phenomina) which can be modeled by an equation which is not continuous
and which does not have continuous derivitives of all orders?
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What is the highest order derivitive which has physical significance?
(ex acelleration, a second order derivitive undoubtedly has significance.
jerk, a third order derivitive has debatable or only minor
significance, I am sure that the fouth order derivitive has been
named but I can think of no place where it is used.)