# Bullets falling back to earth

This is sort of metalwork - it involves lead. I was watching the Iraqies celebrating the capture of Saddam by firing their rifles and guns into the
air. How dangerous are the bullets coming down ? I know they fall back much slower than they leave the gun barrel, but they must still be doing a fair clip. They said 4 people so far have been killed by this but I guess in Iraq its hard to know which bullets came from where. As a few of you know about guns I thought I'd ask here.
Dean.
( I notice they said Saddam was found in a rat infested hidey hole. I bet the rats are glad he's moved out of the neighbourhood ! )
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much
Iraq
Yes, same velocity they went up with many cases on manslaughter have resulted damage can be nasty as the bullet may have aquired a spin or not be in line with the fall
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"Chris Oates" <none> wrote in message

the
fair
That sure doesn't sound right to me. A bullet or any other object fired into the air, let's say straight up to keep it simple, will slow until it finally stops and begins to fall back to earth. I would think the effect of gravity and wind resistance would determine the maximun velocity of the falling bullet (object), not the velocity at which it was fired upward with. The same speed would be realized as if you had simply dropped the bullet (object) at the same altitude from a hot air balloon. Feel free to correct me if I'm wrong.
JTMcC.

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into
finally
gravity
No, you're right. I remember reading about this issue in Popular Science's FYI section several years ago. It's called "terminal velocity", FYI ;-)
I think it said about 9 or 10 people a year die due to people firing into the sky, usually from head and shoulder injuries (really eh?).
Regards,
Robin
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JTMcC wrote:

It would start out with a certain amount of kinetic energy, based on its mass and muzzle velocity. The kinetic energy would be converted to potential energy, minus the work done against air resistance on the way up. On the way down after vertical motion ceased, potential energy is converted into kinetic energy, again minus the energy lost due to air resistance. If there was no air resistance, like a simplified physics problem, the effect of gravity (= stored potential energy) would be determined solely by the initial velocity, and the final velocity on its return to earth would be the same as its initial velocity. In this instance, air resistance is the only loss of energy (from the standpoint of our projectile).
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On Mon, 15 Dec 2003 02:23:58 GMT, the renowned "JTMcC"

Yes, provided it reaches terminal velocity from that height. There was a recent, long and annoying thread on this in sci.electronics.design which I considered x-posting here.. one of the more amusing physics thought experiments was if you fired a bullet from the imaginary surface of a stationary planet with no atmosphere directly vertically (at less muzzle than escape velocity- no problem with that on Earth), it would return at exactly the same speed as it left the muzzle, in the reverse direction. Ouch.
In real conditions, if a relatively heavy bullet isn't tumbling I could see it coming back fast enough to potentially hurt someone (imagine, say, a 180 MPH pointy metal object falling on your skull). But people don't always fire them straight up, which could be worse again. There was apparently a law (called Shannon's Law) passed in Phoenix AZ due to a youth killed from a celebratory gun firing.. common in the Hispanic community.
Gunner probably has all the facts at his fingertips on this...
Best regards, Spehro Pefhany
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A neighbor suddenly had a roof leak after New Year's (in Santa Monica CA) about 10 years ago, and found what he said was a .38 slug that had penetrated the tar paper on his flat roof, but not the plywood under it.
He said it looked like it had hit traveling vertical, and with it's long axis horizontal to the roof. I didn't actually see it, but hearing his account, and knowing he didn't embellish much, think it could have killed someone had it had hit them right... but feel it sure didn't have the energy of a round fired at close range.
Erik
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Spehro Pefhany wrote:

You don't measure bullet speed in miles per hour. But you are pretty close to the maximum terminal velocity. 1mph 1.467 fps so 180 mph = 264 fps. The army found that the maximum terminal velocity of rifle bullets was about 300 mph. For comparison think of a baseball at 80 mph. If the baseball weighs about 2.5 times the bullet, then the energy would be the same as a bullet at 300 fps. Of course a baseball weight many time the average rifle bullet. Or, for another comparison, many air pistols max at about 300 fps. So let's not get carried away with the possible damage of a falling bullet.
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http://www.speff.com
I guess then, it couldn't do a lot of damage. Maybe only kill you.
STeve
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wrote something ......and in reply I say!:
OK, all you bottom posters. Justify the post I am replying to!

I was frightened by the idea of a conspiracy that was causing it all. But then I was terrified that maybe there was no plan, really. Is this unpleasant mess all a mistake?
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wrote something

-snip-
If the id^H^Hpeople took the time to snip, the point would be moot.
I mean, how hard is it to glean the info and snip to the point? It takes, what, 5 seconds, max? Feh!
========================================================= Save the + http://www.diversify.com Endangered SKEETS! + Web Application Programming =========================================================
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Why? Can't you justify your post?
Old Nick wrote:

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You got that right.
Whatever "that" is.
Steve
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*You* justify your quoting the whole thing, too.

[ ... lots of lines snipped ... ]

Really -- top posting is worse than bottom posting in my mind -- because it makes it easier for people to totally forget about what is there (and still has to take up room on thousands of news servers around the world, and to be downloaded in its entirity to all who want to read that one line of new text.
I believe in neither top posting nor bottom posting, but rather interleaved posting (as in this example), with my replies to various parts immediately following those parts, and all excess text not needed to maintain context trimmed.
*Some* newsreaders and news servers will refuse to post an article with more quoted text than new text. I believe that is a good start, as it forces one to trim excess text -- or to really think about it and determine a workaround, if they really feel that all that quoted text is necessary. (Yes, workarounds exist, but a carefully thought-out and trimmed article should normally not need them.)
Enjoy,         DoN.
--
Email: < snipped-for-privacy@d-and-d.com> | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
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SteveB wrote:

I suggest you read Gunner's discourse. Course we could argue about how many angels can dance on the head of pin, but just to keep it in context we could argue about how damaged they would be if they fell off. Or, on a more practical subject, we could discuss the number of people killed by logs falling off logging trucks on the road and how you should hold your breath every time you meet or pass one of those trucks. Yeah, a falling bullet could kill you and people do die from logs falling off a logging truck on a highway, but how many die? Watch out for those 16 inchers from naval guns because even if they fall at only 1/2 fps, they'll still crush your head. Bet you worry about all those particles passing thru you at some large fraction of the speed of light. They can kill you too.
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The phrase is 'terminal velocity' and I suspect that for any modern round fired straight up, this is indeed the determining factor, so I would put my guess in line with yours. As you suggest, there are others here who truly know the answer off the top of their heads.
Jim
================================================= please reply to: JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com =================================================
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JTMcC says...

I'm aware of terminal velocity, and have reached it a time or two. I can reach it while falling from a height, regardless of my velocity in reaching that height, therefor my difference of opinion with the post about the bullet dropping at the same speed it initially rose. I can jump (fall, be pushed out of) an airplane at a height of 1000 ft and I will achieve a certain speed before wind resistance prevents any further increase. I can also be shot from a cannon straight into the air, or simply step off a platform at 1000 feet and still, my velocity toward the earth is limited by drag. If I spend 7 hours climbing to the 1000 foot mark, or ascend in a matter of seconds via F-16, my upward velocity matters not to the downward velocity I attain. That is my take, but then I wasn't even paying attention in H.S. physics.
JTMcC.

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JTMcC wrote:

You are right that it does not matter how you get there, but the initial velocity does matter in projectile motion problems. That is the only energy the projectile has, and it will be converted into a higher potential energy until it has zero kinetic energy at the very top. Putting aside air resistance, initial velocity and elevation is all we need to determine the maximum height the projectile will reach. There are several ways the problem can be solved, but comparing energy states is probably the most intuitive.
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JTMcC says...

energy
energy
problem
We don't care how high it goes, we only care about it's velocity returning to earth, after coming to a theoretical stop after being fired straight up. We are talking about bullets with no energy remaining from the initial firing. I can go out in my fromt yard right now, and fire a .22 caliber, 55 grain projectile into the sky at around 2800 fps (feet per second) or over 4000 fps. Using my original criteria of the bullet flying straight up, until stopped by the force of gravity, and returning to earth via the same gravitational force, do you really believe the bullet fired from a 220 Swift or 22-250 will hit the ground at a greater speed than the one fired from a .223? Again, I was more interested in the girl sitting next to me in H.S. physics class than the math problems, but I'm still pretty sure I'm right.
JTMcC.

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On Tue, 16 Dec 2003 03:10:12 GMT, "JTMcC"

The only difference is the 4000fps bullet will go higher than the 2800 fps bullet. This will only affect the downward speed of the bullet if the max elevation is not high enough to allow the falling bullet to reach terminal velocity. The accelleration of gravity is sufficient to make a 22 caliber projectile reach terminal velocity in significantly less than the verticle distance covered by even a 2700fps projectile, I am sure.

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