# The Naked Scientists Forum

### Author Topic: When a bullet is shot straight upwards, what happens when it returns to earth?  (Read 3483 times)

#### Jacques MAUDOUX

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##### When a bullet is shot straight upwards, what happens when it returns to earth?
« on: 06/05/2008 09:09:44 »
Jacques MAUDOUX  asked the Naked Scientists:

Dear Chris,

On TV, we see some people shooting in the air with their Kalachnikovs and other guns.

What happens to the ammunitions when they fall back on Earth?

Can they be dangerous for the people?

Cordialement,

Jacques MAUDOUX

What do you think?

#### lyner

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##### When a bullet is shot straight upwards, what happens when it returns to earth?
« Reply #1 on: 06/05/2008 10:42:25 »
Yes, it's very dangerous. In an isolated place it's not likely to land on anyone but, in an urban environment, you could easily hit and kill someone. It is, of course, very unlikely that you will fire it directly upwards so you are pretty safe, yourself!
As a lad, I used to do it with my airgun and could hear it land in the grass not far away. (Idiot!)
« Last Edit: 06/05/2008 10:46:15 by sophiecentaur »

#### RD

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##### When a bullet is shot straight upwards, what happens when it returns to earth?
« Reply #2 on: 06/05/2008 12:35:12 »
The velocity of a falling bullet, and the damage it can do, will be much less than when it has just left the gun. The muzzle velocity of a Kalashnikov is about 700 meters per second, the terminal velocity of a falling bullet will be less than 100 meters per second. The kinetic energy is proportional to the square of the velocity, so a falling bullet has less than 1/50th the energy it had when it just left the gun.
Still gonna hurt though.

[This is similar to the "penny dropped from skyscraper" scenario]
http://tafkac.org/science/penny_falling_impact.html
« Last Edit: 06/05/2008 13:28:49 by RD »

#### daveshorts

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##### When a bullet is shot straight upwards, what happens when it returns to earth?
« Reply #3 on: 06/05/2008 13:32:13 »
Yes, this is one of the reasons that soldiers wear tin helmets - a bit of falling metal hitting your shoulder will hurt, and possibly put you in hospital, one hitting your head could kill you.

#### JimBob

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##### When a bullet is shot straight upwards, what happens when it returns to earth?
« Reply #4 on: 07/05/2008 05:54:49 »
Killing wounds, even chest wounds causing death, have been documented in the US from bullets fired randomly into the air - as you are aware, we have more guns here than in the UK.

#### The Naked Scientists Forum

##### When a bullet is shot straight upwards, what happens when it returns to earth?
« Reply #4 on: 07/05/2008 05:54:49 »