🚀 go-pugleaf

In article <3NOV199213001570@csa2.lbl.gov>, sichase@csa2.lbl.gov (SCOTT I CHASE) writes:
> In article <334@mtnmath.UUCP>, paul@mtnmath.UUCP (Paul Budnik) writes...
> Good point.  In practice, whether you get knocked over certainly depends upon
> the time over which the impulse is delivered to your body.  A 1 ton gun 
> would not transfer momentum to you quickly enough to overwhelm your balance.
> But for a typical firearm I don't think that the effect is singificant.
> The impulse from a rifle recoil certainly seems more or less instantaneous
> to me, which presumably means that the impulse lasts for a time shorter 
> than my reaction time, a few tenths of a second.  

Reaction time is not the most important factor. You need to decelerate
the object to a velocity of 0 before it has pushed you to the point that
you loose your balance. To do this requires exerting a level of force
over a given distance. The distance is the amount you can move without
loosing your balance. The force is determined by this distance and
the *energy* of the object. You need to provide a larger force to stop
a low mass object that has the same momentum as a large mass object
because the former has a higher energy.

Bracing yourself can increase the level of force you provide. Being prepared
can increase the distance you are able to move without loosing your balance
as well as the force. If the bullet has one tenth the mass of the gun, the
difference in energy and thus force required is a factor of 10 (assuming a
fixed distance you can move). I do not think bracing and improving your
balance together could provide this big a factor.

Paul Budnik