re: #678 Fat Bastard Vegetarian

The did it on Mythbusters. I don’t think the bullet would kill you coming back down (and you’d have to be a really good shot). I think if it is shot at any angle, though…ooh.

We’re talking kinetic energy vs. potential energy here. A bullet (say, a rifle bullet) is a streamlined object designed to travel through air losing as little velocity as possible due to air resistance. Fired at a high angle (above 60 degrees, let’s say), it will travel to a considerable altitude (about 3/4th of its maximum effective range fired on the horizontal, as it is trying to fight gravity as a nearly straight-back “drag” as opposed to a tangent to its trajectory).

When the bullet gets to the top of its trajectory, like a ballistic missile or a mortar or howitzer round, it will have lost almost all kinetic energy. But due to being higher in the Earth’s gravity field, it will have a store of potential energy roughly equal to the amount of KE it took to get it up there in the first place.

It’s like you or me, standing on the high board at the swimming pool, before jumping off it into the pool. We don’t drift slowly down, and neither does the bullet. It is pulled back down by gravity, and as it falls, its potential energy is converted back to kinetic energy. And being streamlined, it loses no more energy to air resistance coming down than it did going up.

Which means that when it arrives back at ground level, it will be traveling very nearly as fast as it was when it left the muzzle. Point forward, in “Kill ‘em all and let G-d sort ‘em out” mode.

This is why pointing a rifle’s muzzle up is never a good idea. And actually pulling the trigger on a live round with the muzzle up is an Outstandingly Bad Idea.

That bullet will come down somewhere. And whatever it hits, it will destroy.

/The laws of physics do not accept “Oops” as a legitimate defense.

cheers

eon