According to Norminn :
Mark wrote:
OK...
see the white powder on the side of the bookcase.....

that means something....

You've never smashed drywall I assume - it gets _everywhere_ ;-)

i'm not sure what, but probably that the impact was high velocity and
blew the paint plaster etc off the wall and onto the bookcase. If
someone stabed the house I don't think that powder would be there and
there would be more debre on top of the heat register insted of on the
floor.

Wonder what kind of toy could have launced the molding. I remember
bottle bombs, and ........potato guns? Some kind of gun that shot out
potatoes? Those memories are receding )

bungie cords'd do it.

People don't seem to have a good concept of kinetic energy. The
piece of trim probably weighed several pounds, going at any reasonable
speed, being straight at point of impact, would punch through brittle
cedar and OSB/particle board plus drywall held rigidly in place like
a knife through butter.

You could experiment by setting up a chunk of shingle and particle
board held horizontally and rigid, and try dropping a similar piece of trim
straight from 20' or more. Or, graft a piece of trim on the face of a
2 1/2 pound hand sledge and letting fly.

I do high power rocketry. Rockets weighing 20 pounds or more going
to thousands of feet.

You ain't nothing until you see a high power rocket made out of not
much more than cardboard tube[+] coming in ballistically (not under
power, but the nose cone still in place) straight down from even only
a few hundred feet. Depending on soil conditions, you can have
the rocket _completely_ bury itself past the fins. I've seen
small rockets made out of just cardboard (eg: some of the larger
Estes models) weighing less than a pound penetrating 6" or
more in hardpan, which is _much_ tougher than cedar shingle.

This type of mishap is called "shovel recovery" - because you
won't get it back without a shovel.

Another "techie term" is "core sample" - the nose cone
completely detached taking the parachute with it, and you
end up with a "core sample" of dirt in the body tube ;-)

[Yeah, we're pretty serious about safety flying these things.
Large exclusion zones, and in the case of high power,
FAA/MOT event approval. Last big event I was at (200+ pound
rocket to 44K feet at Mach 2.4 was just one of the more
spectacular flights) we had Ministry of Transport officials
out watching and doing the oohs and ahhs with the rest of us ;-)]

[+] Eg fiberglassed cardboard tube or something fairly similar in
properties to a standard plastic thinwall pipe. Eg: PVC septic
tank pipe or central-vac piping.
--
Chris Lewis,

Age and Treachery will Triumph over Youth and Skill
It's not just anyone who gets a Starship Cruiser class named after them.