On 1/30/2017 8:12 PM, Allen Farrington wrote:
And to top it off, there's another 'factor' involved in all of this.
Richard, I had presumed from your questions and statements (i.e., use of
sand, water, etc.) that you're talking about the problem of the rocket
falling to pieces (via a cato or aerodynamically induced damage), and
that was part of your argument about not using things such as BBs or
bullets or nuts. Honestly, I'd rather have one large mass falling down
out of the sky than dozens of smaller ones. Above a certain level,
they're all going to hit terminal velocity (unless they are high-drag
items), AND they're going to disperse. With the larger piece (single
weight in a blob of epoxy), the target area of destruction is going to
be the size of the blob. With a crapload of BBs (not encased in
something), you're going to be in a very large shotgun pattern. All
else being equal, I'd rather be shot at by a single bullet than by a
shotgun blast -- not only is the mass larger, giving me a chance to see
it and get out of the way (perhaps), but the distance I have to move to
be 'safe' is far less. The cone of destruction of a loose mass of
weight is going to be much, much larger -- perhaps even larger than you
can move out of by the time you spot it (if you spot it at all).
David Erbas-White
Now at this speed and energy, before the shell of the cone is destroyed, it and the lead or packed sand has already penetrated together. As long as structural integrity of cone is greater than packed sand, it'll penetrate as a block.
So, Richard, sand doesn't buy you anything over lead for this case. Mass is Mass and at these energies, things happen so fast that you'd be injured all the same. It's a stark reminder that the recent death from a falling nosecone/rocket was an unweighted, plastic nose. It doesn't take much if the hit is in the right spot, sadly.
Is this what you had in mind?
Allen
