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Physics/Firing a gun in the air


Hello: I am curious to know why a bullet fired vertically will come back down at a lethal velocity,and occasionally kill/injure someone.Wouldn't it lose speed  when it reached the zenith of it's trajectory,slow and tumble earthwards,reaching a terminal velocity determined by the pull of gravity and air resistance? Thanks.

It would, indeed. And it would tumble, making it singularly unaerodynamic compared to if it somehow fell point-down.  The thing is, though, it's still made of lead.  Lead has a density over 11 times the density of water.  Therefore, that falling chunk of metal can still injure (and even kill) at such speeds.  Also, the exact nature of the tumbling is a little random.

The question of bullets from vertical gunfire injuring people has some variables, then.  Those variables are therefore why it's such a confounding question...but people are injured and even killed by falling bullets every year.  It would be worse if they were depleted uranium rounds (almost twice the density).


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Dr. Stephen O. Nelson


I can answer most basic physics questions, physics questions about science fiction and everyday observations of physics, etc. I'm also usually good for science fair advice (I'm the regional science fair director). I do not answer homework problems. I will occasionally point out where a homework solution went wrong, though. I'm usually good at explaining odd observations that seem counterintuitive, energy science, nuclear physics, nuclear astrophysics, and alternative theories of physics are my specialties.


I was a physics professor at the University of Texas of the Permian Basin, research in nuclear technology and nuclear astrophysics. My travelling science show saw over 20,000 students of all ages. I taught physics, nuclear chemistry, radiation safety, vacuum technology, and answer tons of questions as I tour schools encouraging students to consider careers in science. I moved on to a non-academic job with more research just recently.

Ph. D. from Duke University in physics, research in nuclear astrophysics reactions, gamma-ray astronomy technology, and advanced nuclear reactors.

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