Aussie wrote on Sep 22
nd, 2010 at 8:06am:
Jabames wrote on Sep 22
nd, 2010 at 12:34am:
more than 3 newtons or 3000 kilonewtons or something like that enough energy to shatter a concrete block, an m16 and ak have a hard time doing that just put holes through. that would be wayyyyyyyyyy more than enough to kill a deer let alone a wild boar, i estimate that that energy would run through any part of the animal and just stop it in its tracks because the energy would have a better time going through soft tissue like vital organs so that could be it, a huge shock to the organs or any body part and it drops, that could be a possibility
Newtons are units of force not energy and 3000 kN is a million times bigger than 3 N; you obviously have no appreciation of the scale of the things you're talking about. Nor does a sling have anywhere near the energy to shatter a concrete block or anything like it. The energy comes from your arm so no whack from a slingstone is going to be harder than a hit from a heavy hammer or similar. It may put a hole or dent in concrete but that's all.
Put in perspective, 3 N is the force generated through dropping a 2/3 pound or so object. 3000kN is the force generated through accelerating a 1 ton object to about 5500 miles per hour over a second. That is somewhat closer to modern artillery than a sling.
But, this originally draws back to kinetic energy, which is E
k=mv
2According to Wikipedia, which is not the most accurate of sources, an AK-47 fires with 2010 joules, rounded to 2000 it becomes much more certain. So, lets see what it is going to take to get a sling up above this. Assume a 2 oz, we are looking at 60 grams, or .06 kg.
2000=.06v
233,333=v
2182 m/s.
About 400 mph.
So, for a sling stone to have as much energy as a bullet out of this one particular assault rifle, it needs to be moving 400 mph. So no, its not going to shatter a concrete block that a bullet barely damages, its comparable energy if you are an amazing shot. If you are that good, and very accurate, then you could take down a deer as humanely as with a gun. The vast majority of us are not able to fire off a sling stone with anywhere near that level of energy however.
Concerning Newtons, that can only be calculated if we know how quickly the stone comes to a stop after impact, and how far it goes in doing so. Its going to be well over 3 newtons in most cases, projectile deceleration upon striking takes a fraction of a second. Not 1 million times that however.