Inertia and Physics.. Paul Chick

[Mark Davidson]

Been offline with some computer problems, but I can see y'all have been
going at it.  Isaac - the day after email was invented, killfiles were
invented.

RicB wrote:

>Instead, let me ask a concrete question. If it takes one newton to
>accelerate an object with a mass of one kilogram at one meter per
>second, and that object bangs into another object... will the first
>object impart a force of exactly one newton upon the second ?

No.

Let's clarify your question.  Acceleration is in m/sec/sec, not m/sec. It is
the change in velocity per second.  The force of impact is a function of
velocity, and the velocity is the acceleration * time.  If you don't define
the duration of the one newton force, you haven't defined the velocity.  So
let's just say you meant 1 second, i.e. a force of one newton on 1 kg for 1
sec, at the end of which time the mass is moving at 1 m/s.  Yes?

Given all that, the answer is still...No.  For lots of reasons.  The main
one being that when you "bang into something"  the impact is likely to be
short.  If you have one of those mythical "perfect elastic" collisions, in a
straight line with something of equal mass, etc, etc, then ALL the energy is
transfered to the second object in a [small] fraction of second.  To
transfer the energy in this short an amount of time requires much higher
force.  Even if you put a really squishy spring between the two objects to
soften the blow and increase the amount of time the force was applied, you
wouldn't have a constant force between the two objects.

-Mark