How do bullets fired into the air kill people when falling, but yet people claim they can't?

Question

I'm puzzled. I've read stories that range from a young boy sititng in a church building having a bullet come through the roof and kill him...to lately, a Florida man was outside watching fireworks when a bullet came down and went through a nostril, through his chin and would have gone into his chest (but it hit and destroyed a medal on a necklace he was wearing). Yet people claim that bullets fired upward slow down first (of course that's true) and then gain speed again falling down, until they reach their terminal velocity. But wait...the claims are that the terminal velocity is not high enough to kill anyone.

So...how are these explanations to be accounted for? Why are people dying from what science and physics people claim is the impossible?

Answer 1

It is not going to land at anything like the speed it went up. The velocity of a bullet leaving a gun is orders of magnitude greater than the terminal velocity it will achieve on the way down. Whether or not it will kill you will depend on the drag coefficient of the bullet which determines the terminal velocity. I suspect the answer is no though unless it lands point down at 90 degrees to the top of your head. A brick will hurt if dropped from 1m onto your hand because of it's mass, a bullet dropped from the same hight won't hurt at all because relativley speaking it has a low mass.

Answer 2

I agree with Doya K. Further, I would like to point out that the limitation of terminal velocity applies only for bodies freely falling from position of rest. Ans so it is said that the mass of bullet being very small the terminal velocity v given by 6*pi*eta*r8v = mg, where eta is the viscosity of air, will be quire small would not kill any one. Bu this consideration does not apply to fast moving objects like bullet in any direction. Yes viscosity of air will reduce its speed but may not reduce it enough to be not fatal during the time of flight from gun to the person.

Answer 3

By the conservation of energy, it should come down just as fast as it left the gun. It starts of with x amount of kinetic energy. That kinetic energy is converted to potential energy as it goes up until it is all potential energy. Then when it comes down that potential energy is converted all the way back to kinetic energy. Now maybe the issue is that it loses its rotational momentum from the rifling when it switches to fall back down, and so is retarded a little more by the air on its way down than it was going up. But honestly I think that should be a small effect and it should come down with deadly force, based on physical laws.



If someone has a bullet go right through him, even through his brain at point blank with full force, it could miss any critical area and still not kill him. That is what seems to have happened in your second example.

Answer 4

A bullet is rotated in the gun (like a screw) when it is fired.

since the bullet experiences no torque during its flight, its angular momentum remains conserved. This means the rotating motion of the bullet is unchanged. so even if the translational speed decreases its rotating motion gives the bullet enough force to pierce through the skin and kill someone.

Answer 5

A 9 mm diameter sphere has a mass of 4.33 g ( 0.00433 kg) , producing a (constant) downward force of (9.81 * 0.00433) 0.0425 N

At terminal velocity , the upward force (due to air drag) balances this.

So: 0.0425 = velocity ^2 * air density (d) * shape drag coefficient (Cd) * frontal area (a)

Air density at sea level = 1.2 kg/cu m , sphere Cd = 0.47 , frontal area = 0.000063617 sq m

Then : velocity = square root ( 0.0425 / ( d * Cd * a ) )

So : terminal velocity = 34.417 m/s (77 mph)

Answer 6

I dont know the physics side but my dad works insurance and he told me a Amish lady was driving down te road a bullet tore through her buggy right into we head and killed her. It might maybe depend on bullet. Some are jacketed, hollow point, soft tip,

Hard tip, pointy, dull, incendiary.

Answer 7

if they are fired straight up they cannot come down with enough force to kill some one... however it is practicably impossible to shoot straight up... in fact the odds are probably 100,000 to one. It only takes a fraction of a degree. The ever so slightly angled gun preserves the momentum and it can come down miles away with enough force to kill some one.

Answer 8

life experience is correct.



It will arrive down at the same level at the same speed that it left the gun.