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View Full Version : OTwhy is easier to stop a bullet than 4kph locomotive having both same kinetic energy



raaaid
10-10-2006, 10:54 AM
if i cover my hand with kevlar ill easily stop a bullet but is imposible to stop a 4 kph 10 ton locomotive with my hand though they have the same kinetic energy, why?

i think the reason is that what counts is momentum and the locomotive has a much bigger one

but if the ability to cause destruction (myself trying to stop the bullet or the locomotive against a wall) depends on momentum consider this:

an unwraping tetherball keeps a constant linear speed therefore momentum can grow up to infinite and so destruction

raaaid
10-10-2006, 10:54 AM
if i cover my hand with kevlar ill easily stop a bullet but is imposible to stop a 4 kph 10 ton locomotive with my hand though they have the same kinetic energy, why?

i think the reason is that what counts is momentum and the locomotive has a much bigger one

but if the ability to cause destruction (myself trying to stop the bullet or the locomotive against a wall) depends on momentum consider this:

an unwraping tetherball keeps a constant linear speed therefore momentum can grow up to infinite and so destruction

PBNA-Boosher
10-10-2006, 10:56 AM
You'll also break your hand.

Brain32
10-10-2006, 10:58 AM
King-kong or Godzilla could easily stop the locomotive, and if locomotive would travel at 4kph, they wouldn't even need the kevlar glove http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif

raaaid
10-10-2006, 10:59 AM
well i can add a cushion but that wouldnt help with the locomotive

Taylortony
10-10-2006, 11:01 AM
You would be better of using a denser material than kevlar.............. your head perhaps ?

http://forums.ubi.com/images/smilies/784.gif http://forums.ubi.com/images/smilies/784.gif http://forums.ubi.com/images/smilies/88.gif http://forums.ubi.com/images/smilies/88.gif http://forums.ubi.com/images/smilies/mockface.gif http://forums.ubi.com/images/smilies/34.gif http://forums.ubi.com/images/smilies/winky.gif http://forums.ubi.com/images/smilies/16x16_smiley-wink.gif

WB_Outlaw
10-10-2006, 11:02 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by raaaid:
i think the reason is that what counts is momentum and the locomotive has a much bigger one
</div></BLOCKQUOTE>

You THINK so? Shouldn't you KNOW? I mean, you've taken all those physics classes haven't you? If your physics teacher didn't explain it well enough, maybe you could ask your "survival teacher".

Momentum = mass x velocity so if the tether ball has a constant linear speed, the momentum does not change, unless the mass does.

--Outlaw.

BSS_Goat
10-10-2006, 11:02 AM
D@mn I missed raaaid.



oh and http://forums.ubi.com/images/smilies/blink.gif

TgD Thunderbolt56
10-10-2006, 11:06 AM
The answer is....INERTIA.

o.k. close this thread now. http://forums.ubi.com/images/smilies/shady.gif

Chuck_Older
10-10-2006, 11:10 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by raaaid:
if i cover my hand with kevlar ill easily stop a bullet but is imposible to stop a 4 kph 10 ton locomotive with my hand though they have the same kinetic energy, why?
</div></BLOCKQUOTE>

You wouldn't stop the bullet. It just wouldn't pass through your hand. Stopping the bullet means no more kinetic energy

Try this: put on a boxing glove, hold your hand up, and have somebody punch the glove. Did your hand stop the punch, or did your hand move?

JG14_Josf
10-10-2006, 11:11 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">if i cover my hand with kevlar ill easily stop a bullet but is imposible to stop a 4 kph 10 ton locomotive with my hand though they have the same kinetic energy, why? </div></BLOCKQUOTE>

It is not impossible - in time.

ElAurens
10-10-2006, 11:13 AM
Don't forget a little thing called mass.

darkhorizon11
10-10-2006, 11:22 AM
Its not kinetic energy, its momentum isn't it?

NekoReaperman
10-10-2006, 11:38 AM
the answer is FORCE....



Mass X accelleration = Force

raaaid
10-10-2006, 12:04 PM
maybe youve seen that video of a guy being shot in the chest with a kevlar on, he doesnt even move,unlike fictitious movies, if he was against a wall he would suffer no harm, cant be said the same about a 4 kmh 10 ton locomotive hitting a guy against a wall

as for the tetherball imagine im in the north pole of an earth with no gravity, i start a tetherball on the opposite sense to earths rotation, i used a minuscule force but i let the tetherball unwrap trillions of km away, then i let the tetherball hit a stick conected to the pole trillions of km long perpendicular to the pole it wont only stop earth but will reverse its sense of rotation

you remember that of give me a point of suport and ill move the world?

an example of amplification of a minusculus force into something huge as tesla postulated

Chuck_Older
10-10-2006, 12:06 PM
Haven't seen the movie. But I guarantee that your hand would move if shot. I can move your hand by throwing a baseball at you, when you catch it

BBB_Hyperion
10-10-2006, 12:17 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by raaaid:
if i cover my hand with kevlar ill easily stop a bullet but is imposible to stop a 4 kph 10 ton locomotive with my hand though they have the same kinetic energy, why?
</div></BLOCKQUOTE>
Ekin =1/2mv^2

1/2 * 10000 * 4 km/h ^2 = 80000
Bullets stoppable with hand
So the bullet must have a speed with 2 g , 3g weight.
8944 km/h,5163 km/h show me that gun http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

x6BL_Brando
10-10-2006, 12:21 PM
Try holding up a high-denomination banknote - works every time with taxis

http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif

Poker_4H
10-10-2006, 12:22 PM
If a 10 ton locomotive hit raaid in the chest while standing against a wall, would we all shoot guns in celebration like they do in the Middle East ??
Hmmmmmm.... good question...

oh, did I get the riddle wrong ?

j/k raaaid !

raaaid
10-10-2006, 12:34 PM
your hand covered with kevlar will move back as much as the guys hand who shoots will move back because of the weapons recoil

El Turo
10-10-2006, 12:35 PM
You're all forgetting that the rails are moving 4kph in the opposite direction of the locomotive.

http://www.comecorrect.net/img/stopHammerTime.jpg

WB_Outlaw
10-10-2006, 12:38 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by raaaid:
maybe youve seen that video of a guy being shot in the chest with a kevlar on, he doesnt even move,unlike fictitious movies, if he was against a wall he would suffer no harm, cant be said the same about a 4 kmh 10 ton locomotive hitting a guy against a wall

as for the tetherball imagine im in the north pole of an earth with no gravity, i start a tetherball on the opposite sense to earths rotation, i used a minuscule force but i let the tetherball unwrap trillions of km away, then i let the tetherball hit a stick conected to the pole trillions of km long perpendicular to the pole it wont only stop earth but will reverse its sense of rotation

you remember that of give me a point of suport and ill move the world?

an example of amplification of a minusculus force into something huge as tesla postulated </div></BLOCKQUOTE>

Once again, you are massively mistaken. A .357 magnum round fired from close range at a person wearing Kevlar will cause extreme blunt trauma. Injuries will range from bad bruises to broken bones to internal organ damange and bleeding depending on the location hit. Even with a vest on penetration into the body can be on the order of inches. A standard vest works by spreading the energy over a wider area, but that's it.

[edit]
You can get steel inserts for some vests that will provide much better protection and stop just about any pistol round from penetrating at all and some rifle rounds. Injuries with this type of hit will be at the edges of the plate and the Kevlar will minimize those greatly.
[end edit]

As far as the tether ball goes, momentum is conserved so it will slow down as the radius increases.

--Outlaw.

Chuck_Older
10-10-2006, 12:56 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by raaaid:
your hand covered with kevlar will move back as much as the guys hand who shoots will move back because of the weapons recoil </div></BLOCKQUOTE>

http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

This is an assumption. Equal and opposite reactions, yes. But you are placing your vector of force 180* behind the bullet, into the shooter, and this makes a neat diagram. but is it accurate?

in any case, my statement was not that the shooter sees no recoil, or that the shooter doesn't do anything at all, it was that your hand will move http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif. What the shooter does or does not do is irrelevant to my statement

DomJScott
10-10-2006, 01:50 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by BBB_Hyperion:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by raaaid:
if i cover my hand with kevlar ill easily stop a bullet but is imposible to stop a 4 kph 10 ton locomotive with my hand though they have the same kinetic energy, why?
</div></BLOCKQUOTE>
Ekin =1/2mv^2

1/2 * 10000 * 4 km/h ^2 = 80000
Bullets stoppable with hand
So the bullet must have a speed with 2 g , 3g weight.
8944 km/h,5163 km/h show me that gun http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif </div></BLOCKQUOTE>

Exactly, or let's make it slightly clearer. Based on a bullet velocity of 1000kmh (or 277m/s) which is slightly slow but not massively ( a WWII MP40 does 380ish ) then the bullet need's to weigh 160grams. A typical bullet weight is no more than 10g. Thus the train would actually have to be travelling at nearer 0.25kmh to be comparable.

StellarRat
10-10-2006, 01:56 PM
Maybe if you knew how much a locomotive really weighted you wouldn't be making this comparison. A diesel electric locomotive weights roughly 230,000lb (104.4t) not 10 tons!

Whirlin_merlin
10-10-2006, 02:16 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">

i think the reason is that what counts is momentum and the locomotive has a much bigger one

an unwraping tetherball keeps a constant linear speed therefore momentum can grow up to infinite and so destruction </div></BLOCKQUOTE>

Okay i was with you about momentum that is what counts but having been hit full on in the face by an unwraping tether ball, i would say 'ouch' but infinite destruction no. Assumimg tetherball is what we Brits call swing ball.

OT and don't try this at home: As a kid my mates and me replaced the string with wire and soaked the ball in petrol. Flaming swing ball!!!
Luckily that one never hit me in the mush.

KIMURA
10-10-2006, 02:31 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by StellarRat:
Maybe if you knew how much a locomotive really weighted you wouldn't be making this comparison. A diesel electric locomotive weights roughly 230,000lb (104.4t) not 10 tons! </div></BLOCKQUOTE>

Here the nostalgic steam loco with a tara of 12000kg that runs sometime through our valley. http://forums.ubi.com/images/smilies/16x16_smiley-very-happy.gif http://forums.ubi.com/images/smilies/16x16_smiley-very-happy.gif
http://mypage.bluewin.ch/a-z/kimura-hei/wb5_20020601_05y.jpg

KIMURA
10-10-2006, 02:33 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by StellarRat:
Maybe if you knew how much a locomotive really weighted you wouldn't be making this comparison. A diesel electric locomotive weights roughly 230,000lb (104.4t) not 10 tons! </div></BLOCKQUOTE>

Here the nostalgic steam loco with a tara of 12000kg that runs sometime through our valley. http://forums.ubi.com/images/smilies/16x16_smiley-very-happy.gif http://forums.ubi.com/images/smilies/16x16_smiley-very-happy.gif
http://www.tramclub-basel.ch/rb/bvb_blt/TramPics/wb5_20020601_05y.jpg

RCAF_Irish_403
10-10-2006, 03:10 PM
This train is going nowhere, fast. Driver, I want off http://forums.ubi.com/images/smilies/16x16_smiley-mad.gif http://forums.ubi.com/images/smilies/crackwhip.gif

Aaron_GT
10-10-2006, 03:19 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">your hand covered with kevlar will move back as much as the guys hand who shoots will move back because of the weapons recoil </div></BLOCKQUOTE>

1. The shooter's gun is braced on a shoulder.

2. The shooter's gun probably weights 9lbs.

So to replicate this you should hold an 7 or 8lb weight in your hand, brace it against your shoulder, then get the bullet fired at your hand. Then it would be comparable.

DomJScott
10-10-2006, 03:20 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by StellarRat:
Maybe if you knew how much a locomotive really weighted you wouldn't be making this comparison. A diesel electric locomotive weights roughly 230,000lb (104.4t) not 10 tons! </div></BLOCKQUOTE>
hehe well there is that, however a better analogy would be a railway wagon which is nearer 10 tons http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif.

ElAurens
10-10-2006, 04:14 PM
Kimura, that is a beautiful little 0-6-0T.

Thanks for posting the pic.

http://forums.ubi.com/images/smilies/16x16_smiley-wink.gif

bun-bun195333
10-10-2006, 04:31 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by raaaid:
if i cover my hand with kevlar ill easily stop a bullet but is imposible to stop a 4 kph 10 ton locomotive with my hand though they have the same kinetic energy, why?
</div></BLOCKQUOTE>

Actually, the answer may surprise you. Bullets are measured in grains and locomotives are made of steel. If you're hit by a sack of grain much of the momentum is dissipated by compression and the friction of the grains rubbing against themselves - another topic entirely - while the lump of steel compresses hardly at all. Next week we'll explain which is faster, a limping duck or Wisconsin.

Sergio_101
10-10-2006, 05:04 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by bun-bun195333:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by raaaid:
if i cover my hand with kevlar ill easily stop a bullet but is imposible to stop a 4 kph 10 ton locomotive with my hand though they have the same kinetic energy, why?
</div></BLOCKQUOTE>

Actually, the answer may surprise you. Bullets are measured in grains and locomotives are made of steel. If you're hit by a sack of grain much of the momentum is dissipated by compression and the friction of the grains rubbing against themselves - another topic entirely - while the lump of steel compresses hardly at all. Next week we'll explain which is faster, a limping duck or Wisconsin. </div></BLOCKQUOTE>



Energy is energy.
It is equally easy to stop them, at least on paper.
Stopping a bullet will release a large proportion on
it's energy as heat.
Depending on the impact media the energy may
be diverted laterally and as heat.

A large object like a locomotive will be nearly
100% motion. Very little energy will be released as heat.
Low speed means a lot of force/pressure.

But the energy converted will be exactly the same.
By the way, cover your hane in kevlar and shoot
it with any center fire rifle and it will
blow right through.
Make the rifle a .30 cal class (8mm Mauser, .30-06) or bigger
and if it does not punch through it will likely tear your hand off.

Sergio

iQv_nuclear
10-10-2006, 05:12 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Chuck_Older:
I can move your hand by throwing a baseball at you, when you catch it </div></BLOCKQUOTE> Only if he doesn't know how to play baseball.

I'm taking my first physics course this year and thoroughly enjoying it. Unfortunately, I don't know enough yet (formulas) to really contribute to this discussion. So, keep talking and I can learn more http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

AKA_TAGERT
10-10-2006, 06:41 PM
what is really amazing is the milage raaid gets out of these posts

Scragbat
10-10-2006, 07:35 PM
I'm pink, therefore I'm spam... http://forums.ubi.com/images/smilies/16x16_smiley-wink.gif

FritzGryphon
10-10-2006, 10:26 PM
The KE is not even close. Consider a 30 gram bullet at 500 m/s and a very small 20 ton locomotive at 1 m/s.

20,000 kg x 1 m/s squared = 200,000j

0.03 kg x 500 m/s squared = 45,000j

And real locomotives weigh hundreds or thousands of tons, not 20. It's also questionable why you'd be hit by a train going 3 km/h.

tHeBaLrOgRoCkS
10-10-2006, 10:57 PM
BECAUSE ITS A FAKKING TRAIN and you dont wear your underpants on the outside of your trousers.......or do you?
http://forums.ubi.com/images/smilies/blink.gif

BiscuitKnight
10-10-2006, 11:08 PM
You're all wrong http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

Pirschjaeger
10-10-2006, 11:30 PM
Forces in motion stay in motion until they hit something much bigger or heavier.

Another possible reason is that it is much easier to get a gun license than a locomotive license. http://forums.ubi.com/images/smilies/16x16_smiley-wink.gif

Fritz

Pirschjaeger
10-10-2006, 11:32 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by AKA_TAGERT:
what is really amazing is the milage raaid gets out of these posts </div></BLOCKQUOTE>

Tagert's Posts: 1206

Tagert's Posts in Raaaid Threads: 826

Ha ha ha, you are right: totally amazing. http://forums.ubi.com/images/smilies/16x16_smiley-very-happy.gif

Siwarrior
10-11-2006, 12:23 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by raaaid:
if i cover my hand with kevlar ill easily stop a bullet but is imposible to stop a 4 kph 10 ton locomotive with my hand though they have the same kinetic energy, why?

i think the reason is that what counts is momentum and the locomotive has a much bigger one

but if the ability to cause destruction (myself trying to stop the bullet or the locomotive against a wall) depends on momentum consider this:

an unwraping tetherball keeps a constant linear speed therefore momentum can grow up to infinite and so destruction </div></BLOCKQUOTE>

ok i just got out of bed...
raaaid i want you have


double

fordfan25
10-11-2006, 12:27 AM
i heard very small stones float

fordfan25
10-11-2006, 12:28 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by WB_Outlaw:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by raaaid:
maybe youve seen that video of a guy being shot in the chest with a kevlar on, he doesnt even move,unlike fictitious movies, if he was against a wall he would suffer no harm, cant be said the same about a 4 kmh 10 ton locomotive hitting a guy against a wall

as for the tetherball imagine im in the north pole of an earth with no gravity, i start a tetherball on the opposite sense to earths rotation, i used a minuscule force but i let the tetherball unwrap trillions of km away, then i let the tetherball hit a stick conected to the pole trillions of km long perpendicular to the pole it wont only stop earth but will reverse its sense of rotation

you remember that of give me a point of suport and ill move the world?

an example of amplification of a minusculus force into something huge as tesla postulated </div></BLOCKQUOTE>

Once again, you are massively mistaken. A .357 magnum round fired from close range at a person wearing Kevlar will cause extreme blunt trauma. Injuries will range from bad bruises to broken bones to internal organ damange and bleeding depending on the location hit. Even with a vest on penetration into the body can be on the order of inches. A standard vest works by spreading the energy over a wider area, but that's it.

[edit]
You can get steel inserts for some vests that will provide much better protection and stop just about any pistol round from penetrating at all and some rifle rounds. Injuries with this type of hit will be at the edges of the plate and the Kevlar will minimize those greatly.
[end edit]

As far as the tether ball goes, momentum is conserved so it will slow down as the radius increases.

--Outlaw. </div></BLOCKQUOTE>a 357mag will pass threw most kavlar vest like a hot kniofe threw butter at close range. i have seen it.... i was a part of the test http://forums.ubi.com/images/smilies/51.gif

fordfan25
10-11-2006, 12:30 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by AKA_TAGERT:
what is really amazing is the milage raaid gets out of these posts </div></BLOCKQUOTE>i think we are all going to be just a little sick when we find out that Raaaaid is actualy CRASH and has been fishing and owning everyone.

fordfan25
10-11-2006, 12:32 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by bun-bun195333:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by raaaid:
if i cover my hand with kevlar ill easily stop a bullet but is imposible to stop a 4 kph 10 ton locomotive with my hand though they have the same kinetic energy, why?
</div></BLOCKQUOTE>

Actually, the answer may surprise you. Bullets are measured in grains and locomotives are made of steel. If you're hit by a sack of grain much of the momentum is dissipated by compression and the friction of the grains rubbing against themselves - another topic entirely - while the lump of steel compresses hardly at all. Next week we'll explain which is faster, a limping duck or Wisconsin. </div></BLOCKQUOTE> http://forums.ubi.com/images/smilies/88.gif wich weighs more a LB of feathers or a LB of iorn

Pirschjaeger
10-11-2006, 12:33 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by fordfan25:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by WB_Outlaw:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by raaaid:
maybe youve seen that video of a guy being shot in the chest with a kevlar on, he doesnt even move,unlike fictitious movies, if he was against a wall he would suffer no harm, cant be said the same about a 4 kmh 10 ton locomotive hitting a guy against a wall

as for the tetherball imagine im in the north pole of an earth with no gravity, i start a tetherball on the opposite sense to earths rotation, i used a minuscule force but i let the tetherball unwrap trillions of km away, then i let the tetherball hit a stick conected to the pole trillions of km long perpendicular to the pole it wont only stop earth but will reverse its sense of rotation

you remember that of give me a point of suport and ill move the world?

an example of amplification of a minusculus force into something huge as tesla postulated </div></BLOCKQUOTE>

Once again, you are massively mistaken. A .357 magnum round fired from close range at a person wearing Kevlar will cause extreme blunt trauma. Injuries will range from bad bruises to broken bones to internal organ damange and bleeding depending on the location hit. Even with a vest on penetration into the body can be on the order of inches. A standard vest works by spreading the energy over a wider area, but that's it.

[edit]
You can get steel inserts for some vests that will provide much better protection and stop just about any pistol round from penetrating at all and some rifle rounds. Injuries with this type of hit will be at the edges of the plate and the Kevlar will minimize those greatly.
[end edit]

As far as the tether ball goes, momentum is conserved so it will slow down as the radius increases.

--Outlaw. </div></BLOCKQUOTE>a 357mag will pass threw most kavlar vest like a hot kniofe threw butter at close range. i have seen it.... i was a part of the test http://forums.ubi.com/images/smilies/51.gif </div></BLOCKQUOTE>

You should see what a locomotive can do to a 357 mag and a kevlar vest. http://forums.ubi.com/images/smilies/winky.gif

Siwarrior
10-11-2006, 12:42 AM
one of oleg locomotives http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif :P

El Turo
10-11-2006, 02:32 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">You should see what a locomotive can do to a 357 mag and a kevlar vest. </div></BLOCKQUOTE>


LOL

WB_Outlaw
10-11-2006, 05:48 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by fordfan25:
a 357mag will pass threw most kavlar vest like a hot kniofe threw butter at close range. i have seen it.... i was a part of the test http://forums.ubi.com/images/smilies/51.gif </div></BLOCKQUOTE>

A NIJ Level II vest will stop a .357 JSP round at 1395 fps. While some loads are hotter than others, 1395 fps looks to be a little towards the high end of most factory ammo.

The NIJ maximum allowable penetration into the body while wearing a vest is 1.7".

--Outlaw.

DuxCorvan
10-11-2006, 12:33 PM
What's all the fuzz about. Bullets, locomotives... all the same:
http://openorthodoxie.literatesolutions.org/Members/vanGoor/Politica/Superman.jpg
http://premium1.uploadit.org/DuxCorvan//superman.jpg

fordfan25
10-11-2006, 02:42 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Siwarrior:
one of oleg locomotives http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif :P </div></BLOCKQUOTE>made of delta wood

Fork-N-spoon
10-11-2006, 02:47 PM
First, a traffic cop can hold up dozens of cars with one hand. Second, if Superman can stop bullets, why is it that he always ducks when somebody throws the empty pistol at him?

Mysticpuma2003
10-11-2006, 05:27 PM
I'd rather have a go at the locomotive. If it's one that's running in England.

I'd be able to get a cup of tea and a bacon buttie before the train got to me.....wouldn't fancy the bullet though! http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

DuxCorvan
10-11-2006, 06:04 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Fork-N-spoon:
If Superman can stop bullets, why is it that he always ducks when somebody throws the empty pistol at him? </div></BLOCKQUOTE>

Superman collects pistols. He doesn't want to damage it with his iron nose, so he lets it fly away. He knows he can take it intact after he makes a porridge with the bad guy.

Pirschjaeger
10-11-2006, 10:11 PM
Superman doesn't collect pistols, he just doesn't want to get incriminating forehead prints on the handle.

He does however collect leotards.

Maybe he's afraid the pistol might make a run in his leotards. http://forums.ubi.com/images/smilies/blink.gif

SnapdLikeAMutha
01-22-2007, 09:22 AM
OK, so a Tiger tank going 20mph leaves New York heading east, at the same time as a 0.50" bullet going 3000fps leaves London heading west. If the 0.50" is nerfed and the Tiger has uberclimb, at what time should I take my pies out the oven?

Irish_Rogues
01-22-2007, 09:40 AM
http://forums.ubi.com/images/smilies/touche.gif

CAF96th_Sillyak
01-22-2007, 10:33 AM
raiiid please take a basic kinematics class at your local university.

Swivet
01-22-2007, 11:02 AM
http://forums.ubi.com/images/smilies/shady.gif http://forums.ubi.com/images/smilies/shady.gif...Never ceases to amaze me, the OT questions asked here, but i think the Train has sligthly MORE mass than a bullet http://forums.ubi.com/images/smilies/35.gif

flox
01-22-2007, 11:35 AM
Another side-effect of the forums reverting back to October: revived raaaid topics. Ugh. http://forums.ubi.com/images/smilies/35.gif

DIRTY-MAC
01-22-2007, 11:45 AM
Hard To Stop A Train
http://www.youtube.com/watch?v=WYiUAIdYvpk

Rattler68
01-22-2007, 11:48 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by BBB_Hyperion:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by raaaid:
if i cover my hand with kevlar ill easily stop a bullet but is imposible to stop a 4 kph 10 ton locomotive with my hand though they have the same kinetic energy, why?
</div></BLOCKQUOTE>
Ekin =1/2mv^2

1/2 * 10000 * 4 km/h ^2 = 80000
Bullets stoppable with hand
So the bullet must have a speed with 2 g , 3g weight.
8944 km/h,5163 km/h show me that gun http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif </div></BLOCKQUOTE>
Remember in this formula, in SI units, the mass is in kg, and the vel. is in m/s. .5x10000x1.11111^2=6173 J.
The 3 g bullet would be travelling at 2028 m/s; still, it's quite high.

MB_Avro_UK
01-22-2007, 12:25 PM
Why the **** am I posting this http://forums.ubi.com/images/smilies/blink.gif

Sooo...if the bullet is fired head on at the kevlar armoured train...will the train stop http://forums.ubi.com/groupee_common/emoticons/icon_cool.gif

I need a lie down in a darkened room,
MB_Avro.